+++ /dev/null
-What: devfs
-Date: July 2005
-Contact: Greg Kroah-Hartman <gregkh@suse.de>
-Description:
- devfs has been unmaintained for a number of years, has unfixable
- races, contains a naming policy within the kernel that is
- against the LSB, and can be replaced by using udev.
- The files fs/devfs/*, include/linux/devfs_fs*.h will be removed,
- along with the the assorted devfs function calls throughout the
- kernel tree.
-
-Users:
-
--- /dev/null
+What: devfs
+Date: July 2005 (scheduled), finally removed in kernel v2.6.18
+Contact: Greg Kroah-Hartman <gregkh@suse.de>
+Description:
+ devfs has been unmaintained for a number of years, has unfixable
+ races, contains a naming policy within the kernel that is
+ against the LSB, and can be replaced by using udev.
+ The files fs/devfs/*, include/linux/devfs_fs*.h were removed,
+ along with the the assorted devfs function calls throughout the
+ kernel tree.
+
+Users:
--- /dev/null
+What: /sys/power/
+Date: August 2006
+Contact: Rafael J. Wysocki <rjw@sisk.pl>
+Description:
+ The /sys/power directory will contain files that will
+ provide a unified interface to the power management
+ subsystem.
+
+What: /sys/power/state
+Date: August 2006
+Contact: Rafael J. Wysocki <rjw@sisk.pl>
+Description:
+ The /sys/power/state file controls the system power state.
+ Reading from this file returns what states are supported,
+ which is hard-coded to 'standby' (Power-On Suspend), 'mem'
+ (Suspend-to-RAM), and 'disk' (Suspend-to-Disk).
+
+ Writing to this file one of these strings causes the system to
+ transition into that state. Please see the file
+ Documentation/power/states.txt for a description of each of
+ these states.
+
+What: /sys/power/disk
+Date: August 2006
+Contact: Rafael J. Wysocki <rjw@sisk.pl>
+Description:
+ The /sys/power/disk file controls the operating mode of the
+ suspend-to-disk mechanism. Reading from this file returns
+ the name of the method by which the system will be put to
+ sleep on the next suspend. There are four methods supported:
+ 'firmware' - means that the memory image will be saved to disk
+ by some firmware, in which case we also assume that the
+ firmware will handle the system suspend.
+ 'platform' - the memory image will be saved by the kernel and
+ the system will be put to sleep by the platform driver (e.g.
+ ACPI or other PM registers).
+ 'shutdown' - the memory image will be saved by the kernel and
+ the system will be powered off.
+ 'reboot' - the memory image will be saved by the kernel and
+ the system will be rebooted.
+
+ The suspend-to-disk method may be chosen by writing to this
+ file one of the accepted strings:
+
+ 'firmware'
+ 'platform'
+ 'shutdown'
+ 'reboot'
+
+ It will only change to 'firmware' or 'platform' if the system
+ supports that.
+
+What: /sys/power/image_size
+Date: August 2006
+Contact: Rafael J. Wysocki <rjw@sisk.pl>
+Description:
+ The /sys/power/image_size file controls the size of the image
+ created by the suspend-to-disk mechanism. It can be written a
+ string representing a non-negative integer that will be used
+ as an upper limit of the image size, in bytes. The kernel's
+ suspend-to-disk code will do its best to ensure the image size
+ will not exceed this number. However, if it turns out to be
+ impossible, the kernel will try to suspend anyway using the
+ smallest image possible. In particular, if "0" is written to
+ this file, the suspend image will be as small as possible.
+
+ Reading from this file will display the current image size
+ limit, which is set to 500 MB by default.
+
+What: /sys/power/pm_trace
+Date: August 2006
+Contact: Rafael J. Wysocki <rjw@sisk.pl>
+Description:
+ The /sys/power/pm_trace file controls the code which saves the
+ last PM event point in the RTC across reboots, so that you can
+ debug a machine that just hangs during suspend (or more
+ commonly, during resume). Namely, the RTC is only used to save
+ the last PM event point if this file contains '1'. Initially
+ it contains '0' which may be changed to '1' by writing a
+ string representing a nonzero integer into it.
+
+ To use this debugging feature you should attempt to suspend
+ the machine, then reboot it and run
+
+ dmesg -s 1000000 | grep 'hash matches'
+
+ CAUTION: Using it will cause your machine's real-time (CMOS)
+ clock to be set to a random invalid time after a resume.
---------------------------
+What: /sys/devices/.../power/state
+ dev->power.power_state
+ dpm_runtime_{suspend,resume)()
+When: July 2007
+Why: Broken design for runtime control over driver power states, confusing
+ driver-internal runtime power management with: mechanisms to support
+ system-wide sleep state transitions; event codes that distinguish
+ different phases of swsusp "sleep" transitions; and userspace policy
+ inputs. This framework was never widely used, and most attempts to
+ use it were broken. Drivers should instead be exposing domain-specific
+ interfaces either to kernel or to userspace.
+Who: Pavel Machek <pavel@suse.cz>
+
+---------------------------
+
What: RAW driver (CONFIG_RAW_DRIVER)
When: December 2005
Why: declared obsolete since kernel 2.6.3
It is not clear if anyone is still using it.
Who: Stephen Hemminger <shemminger@osdl.org>
+---------------------------
+
+
+What: PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
+When: Oktober 2008
+Why: The stacking of class devices makes these values misleading and
+ inconsistent.
+ Class devices should not carry any of these properties, and bus
+ devices have SUBSYTEM and DRIVER as a replacement.
+Who: Kay Sievers <kay.sievers@suse.de>
+
+---------------------------
+Most of the code in Linux is device drivers, so most of the Linux power
+management code is also driver-specific. Most drivers will do very little;
+others, especially for platforms with small batteries (like cell phones),
+will do a lot.
+
+This writeup gives an overview of how drivers interact with system-wide
+power management goals, emphasizing the models and interfaces that are
+shared by everything that hooks up to the driver model core. Read it as
+background for the domain-specific work you'd do with any specific driver.
+
+
+Two Models for Device Power Management
+======================================
+Drivers will use one or both of these models to put devices into low-power
+states:
+
+ System Sleep model:
+ Drivers can enter low power states as part of entering system-wide
+ low-power states like "suspend-to-ram", or (mostly for systems with
+ disks) "hibernate" (suspend-to-disk).
+
+ This is something that device, bus, and class drivers collaborate on
+ by implementing various role-specific suspend and resume methods to
+ cleanly power down hardware and software subsystems, then reactivate
+ them without loss of data.
+
+ Some drivers can manage hardware wakeup events, which make the system
+ leave that low-power state. This feature may be disabled using the
+ relevant /sys/devices/.../power/wakeup file; enabling it may cost some
+ power usage, but let the whole system enter low power states more often.
+
+ Runtime Power Management model:
+ Drivers may also enter low power states while the system is running,
+ independently of other power management activity. Upstream drivers
+ will normally not know (or care) if the device is in some low power
+ state when issuing requests; the driver will auto-resume anything
+ that's needed when it gets a request.
+
+ This doesn't have, or need much infrastructure; it's just something you
+ should do when writing your drivers. For example, clk_disable() unused
+ clocks as part of minimizing power drain for currently-unused hardware.
+ Of course, sometimes clusters of drivers will collaborate with each
+ other, which could involve task-specific power management.
+
+There's not a lot to be said about those low power states except that they
+are very system-specific, and often device-specific. Also, that if enough
+drivers put themselves into low power states (at "runtime"), the effect may be
+the same as entering some system-wide low-power state (system sleep) ... and
+that synergies exist, so that several drivers using runtime pm might put the
+system into a state where even deeper power saving options are available.
+
+Most suspended devices will have quiesced all I/O: no more DMA or irqs, no
+more data read or written, and requests from upstream drivers are no longer
+accepted. A given bus or platform may have different requirements though.
+
+Examples of hardware wakeup events include an alarm from a real time clock,
+network wake-on-LAN packets, keyboard or mouse activity, and media insertion
+or removal (for PCMCIA, MMC/SD, USB, and so on).
+
+
+Interfaces for Entering System Sleep States
+===========================================
+Most of the programming interfaces a device driver needs to know about
+relate to that first model: entering a system-wide low power state,
+rather than just minimizing power consumption by one device.
+
+
+Bus Driver Methods
+------------------
+The core methods to suspend and resume devices reside in struct bus_type.
+These are mostly of interest to people writing infrastructure for busses
+like PCI or USB, or because they define the primitives that device drivers
+may need to apply in domain-specific ways to their devices:
-Device Power Management
+struct bus_type {
+ ...
+ int (*suspend)(struct device *dev, pm_message_t state);
+ int (*suspend_late)(struct device *dev, pm_message_t state);
+ int (*resume_early)(struct device *dev);
+ int (*resume)(struct device *dev);
+};
-Device power management encompasses two areas - the ability to save
-state and transition a device to a low-power state when the system is
-entering a low-power state; and the ability to transition a device to
-a low-power state while the system is running (and independently of
-any other power management activity).
+Bus drivers implement those methods as appropriate for the hardware and
+the drivers using it; PCI works differently from USB, and so on. Not many
+people write bus drivers; most driver code is a "device driver" that
+builds on top of bus-specific framework code.
+
+For more information on these driver calls, see the description later;
+they are called in phases for every device, respecting the parent-child
+sequencing in the driver model tree. Note that as this is being written,
+only the suspend() and resume() are widely available; not many bus drivers
+leverage all of those phases, or pass them down to lower driver levels.
+
+
+/sys/devices/.../power/wakeup files
+-----------------------------------
+All devices in the driver model have two flags to control handling of
+wakeup events, which are hardware signals that can force the device and/or
+system out of a low power state. These are initialized by bus or device
+driver code using device_init_wakeup(dev,can_wakeup).
+
+The "can_wakeup" flag just records whether the device (and its driver) can
+physically support wakeup events. When that flag is clear, the sysfs
+"wakeup" file is empty, and device_may_wakeup() returns false.
+
+For devices that can issue wakeup events, a separate flag controls whether
+that device should try to use its wakeup mechanism. The initial value of
+device_may_wakeup() will be true, so that the device's "wakeup" file holds
+the value "enabled". Userspace can change that to "disabled" so that
+device_may_wakeup() returns false; or change it back to "enabled" (so that
+it returns true again).
+
+
+EXAMPLE: PCI Device Driver Methods
+-----------------------------------
+PCI framework software calls these methods when the PCI device driver bound
+to a device device has provided them:
+
+struct pci_driver {
+ ...
+ int (*suspend)(struct pci_device *pdev, pm_message_t state);
+ int (*suspend_late)(struct pci_device *pdev, pm_message_t state);
+
+ int (*resume_early)(struct pci_device *pdev);
+ int (*resume)(struct pci_device *pdev);
+};
+Drivers will implement those methods, and call PCI-specific procedures
+like pci_set_power_state(), pci_enable_wake(), pci_save_state(), and
+pci_restore_state() to manage PCI-specific mechanisms. (PCI config space
+could be saved during driver probe, if it weren't for the fact that some
+systems rely on userspace tweaking using setpci.) Devices are suspended
+before their bridges enter low power states, and likewise bridges resume
+before their devices.
+
+
+Upper Layers of Driver Stacks
+-----------------------------
+Device drivers generally have at least two interfaces, and the methods
+sketched above are the ones which apply to the lower level (nearer PCI, USB,
+or other bus hardware). The network and block layers are examples of upper
+level interfaces, as is a character device talking to userspace.
+
+Power management requests normally need to flow through those upper levels,
+which often use domain-oriented requests like "blank that screen". In
+some cases those upper levels will have power management intelligence that
+relates to end-user activity, or other devices that work in cooperation.
+
+When those interfaces are structured using class interfaces, there is a
+standard way to have the upper layer stop issuing requests to a given
+class device (and restart later):
+
+struct class {
+ ...
+ int (*suspend)(struct device *dev, pm_message_t state);
+ int (*resume)(struct device *dev);
+};
-Methods
+Those calls are issued in specific phases of the process by which the
+system enters a low power "suspend" state, or resumes from it.
+
+
+Calling Drivers to Enter System Sleep States
+============================================
+When the system enters a low power state, each device's driver is asked
+to suspend the device by putting it into state compatible with the target
+system state. That's usually some version of "off", but the details are
+system-specific. Also, wakeup-enabled devices will usually stay partly
+functional in order to wake the system.
+
+When the system leaves that low power state, the device's driver is asked
+to resume it. The suspend and resume operations always go together, and
+both are multi-phase operations.
+
+For simple drivers, suspend might quiesce the device using the class code
+and then turn its hardware as "off" as possible with late_suspend. The
+matching resume calls would then completely reinitialize the hardware
+before reactivating its class I/O queues.
+
+More power-aware drivers drivers will use more than one device low power
+state, either at runtime or during system sleep states, and might trigger
+system wakeup events.
+
+
+Call Sequence Guarantees
+------------------------
+To ensure that bridges and similar links needed to talk to a device are
+available when the device is suspended or resumed, the device tree is
+walked in a bottom-up order to suspend devices. A top-down order is
+used to resume those devices.
+
+The ordering of the device tree is defined by the order in which devices
+get registered: a child can never be registered, probed or resumed before
+its parent; and can't be removed or suspended after that parent.
+
+The policy is that the device tree should match hardware bus topology.
+(Or at least the control bus, for devices which use multiple busses.)
+
+
+Suspending Devices
+------------------
+Suspending a given device is done in several phases. Suspending the
+system always includes every phase, executing calls for every device
+before the next phase begins. Not all busses or classes support all
+these callbacks; and not all drivers use all the callbacks.
+
+The phases are seen by driver notifications issued in this order:
+
+ 1 class.suspend(dev, message) is called after tasks are frozen, for
+ devices associated with a class that has such a method. This
+ method may sleep.
+
+ Since I/O activity usually comes from such higher layers, this is
+ a good place to quiesce all drivers of a given type (and keep such
+ code out of those drivers).
+
+ 2 bus.suspend(dev, message) is called next. This method may sleep,
+ and is often morphed into a device driver call with bus-specific
+ parameters and/or rules.
+
+ This call should handle parts of device suspend logic that require
+ sleeping. It probably does work to quiesce the device which hasn't
+ been abstracted into class.suspend() or bus.suspend_late().
+
+ 3 bus.suspend_late(dev, message) is called with IRQs disabled, and
+ with only one CPU active. Until the bus.resume_early() phase
+ completes (see later), IRQs are not enabled again. This method
+ won't be exposed by all busses; for message based busses like USB,
+ I2C, or SPI, device interactions normally require IRQs. This bus
+ call may be morphed into a driver call with bus-specific parameters.
+
+ This call might save low level hardware state that might otherwise
+ be lost in the upcoming low power state, and actually put the
+ device into a low power state ... so that in some cases the device
+ may stay partly usable until this late. This "late" call may also
+ help when coping with hardware that behaves badly.
+
+The pm_message_t parameter is currently used to refine those semantics
+(described later).
+
+At the end of those phases, drivers should normally have stopped all I/O
+transactions (DMA, IRQs), saved enough state that they can re-initialize
+or restore previous state (as needed by the hardware), and placed the
+device into a low-power state. On many platforms they will also use
+clk_disable() to gate off one or more clock sources; sometimes they will
+also switch off power supplies, or reduce voltages. Drivers which have
+runtime PM support may already have performed some or all of the steps
+needed to prepare for the upcoming system sleep state.
+
+When any driver sees that its device_can_wakeup(dev), it should make sure
+to use the relevant hardware signals to trigger a system wakeup event.
+For example, enable_irq_wake() might identify GPIO signals hooked up to
+a switch or other external hardware, and pci_enable_wake() does something
+similar for PCI's PME# signal.
+
+If a driver (or bus, or class) fails it suspend method, the system won't
+enter the desired low power state; it will resume all the devices it's
+suspended so far.
+
+Note that drivers may need to perform different actions based on the target
+system lowpower/sleep state. At this writing, there are only platform
+specific APIs through which drivers could determine those target states.
+
+
+Device Low Power (suspend) States
+---------------------------------
+Device low-power states aren't very standard. One device might only handle
+"on" and "off, while another might support a dozen different versions of
+"on" (how many engines are active?), plus a state that gets back to "on"
+faster than from a full "off".
+
+Some busses define rules about what different suspend states mean. PCI
+gives one example: after the suspend sequence completes, a non-legacy
+PCI device may not perform DMA or issue IRQs, and any wakeup events it
+issues would be issued through the PME# bus signal. Plus, there are
+several PCI-standard device states, some of which are optional.
+
+In contrast, integrated system-on-chip processors often use irqs as the
+wakeup event sources (so drivers would call enable_irq_wake) and might
+be able to treat DMA completion as a wakeup event (sometimes DMA can stay
+active too, it'd only be the CPU and some peripherals that sleep).
+
+Some details here may be platform-specific. Systems may have devices that
+can be fully active in certain sleep states, such as an LCD display that's
+refreshed using DMA while most of the system is sleeping lightly ... and
+its frame buffer might even be updated by a DSP or other non-Linux CPU while
+the Linux control processor stays idle.
+
+Moreover, the specific actions taken may depend on the target system state.
+One target system state might allow a given device to be very operational;
+another might require a hard shut down with re-initialization on resume.
+And two different target systems might use the same device in different
+ways; the aforementioned LCD might be active in one product's "standby",
+but a different product using the same SOC might work differently.
+
+
+Meaning of pm_message_t.event
+-----------------------------
+Parameters to suspend calls include the device affected and a message of
+type pm_message_t, which has one field: the event. If driver does not
+recognize the event code, suspend calls may abort the request and return
+a negative errno. However, most drivers will be fine if they implement
+PM_EVENT_SUSPEND semantics for all messages.
+
+The event codes are used to refine the goal of suspending the device, and
+mostly matter when creating or resuming system memory image snapshots, as
+used with suspend-to-disk:
+
+ PM_EVENT_SUSPEND -- quiesce the driver and put hardware into a low-power
+ state. When used with system sleep states like "suspend-to-RAM" or
+ "standby", the upcoming resume() call will often be able to rely on
+ state kept in hardware, or issue system wakeup events. When used
+ instead with suspend-to-disk, few devices support this capability;
+ most are completely powered off.
+
+ PM_EVENT_FREEZE -- quiesce the driver, but don't necessarily change into
+ any low power mode. A system snapshot is about to be taken, often
+ followed by a call to the driver's resume() method. Neither wakeup
+ events nor DMA are allowed.
+
+ PM_EVENT_PRETHAW -- quiesce the driver, knowing that the upcoming resume()
+ will restore a suspend-to-disk snapshot from a different kernel image.
+ Drivers that are smart enough to look at their hardware state during
+ resume() processing need that state to be correct ... a PRETHAW could
+ be used to invalidate that state (by resetting the device), like a
+ shutdown() invocation would before a kexec() or system halt. Other
+ drivers might handle this the same way as PM_EVENT_FREEZE. Neither
+ wakeup events nor DMA are allowed.
+
+To enter "standby" (ACPI S1) or "Suspend to RAM" (STR, ACPI S3) states, or
+the similarly named APM states, only PM_EVENT_SUSPEND is used; for "Suspend
+to Disk" (STD, hibernate, ACPI S4), all of those event codes are used.
+
+There's also PM_EVENT_ON, a value which never appears as a suspend event
+but is sometimes used to record the "not suspended" device state.
+
+
+Resuming Devices
+----------------
+Resuming is done in multiple phases, much like suspending, with all
+devices processing each phase's calls before the next phase begins.
+
+The phases are seen by driver notifications issued in this order:
+
+ 1 bus.resume_early(dev) is called with IRQs disabled, and with
+ only one CPU active. As with bus.suspend_late(), this method
+ won't be supported on busses that require IRQs in order to
+ interact with devices.
+
+ This reverses the effects of bus.suspend_late().
+
+ 2 bus.resume(dev) is called next. This may be morphed into a device
+ driver call with bus-specific parameters; implementations may sleep.
+
+ This reverses the effects of bus.suspend().
+
+ 3 class.resume(dev) is called for devices associated with a class
+ that has such a method. Implementations may sleep.
+
+ This reverses the effects of class.suspend(), and would usually
+ reactivate the device's I/O queue.
+
+At the end of those phases, drivers should normally be as functional as
+they were before suspending: I/O can be performed using DMA and IRQs, and
+the relevant clocks are gated on. The device need not be "fully on"; it
+might be in a runtime lowpower/suspend state that acts as if it were.
+
+However, the details here may again be platform-specific. For example,
+some systems support multiple "run" states, and the mode in effect at
+the end of resume() might not be the one which preceded suspension.
+That means availability of certain clocks or power supplies changed,
+which could easily affect how a driver works.
+
+
+Drivers need to be able to handle hardware which has been reset since the
+suspend methods were called, for example by complete reinitialization.
+This may be the hardest part, and the one most protected by NDA'd documents
+and chip errata. It's simplest if the hardware state hasn't changed since
+the suspend() was called, but that can't always be guaranteed.
+
+Drivers must also be prepared to notice that the device has been removed
+while the system was powered off, whenever that's physically possible.
+PCMCIA, MMC, USB, Firewire, SCSI, and even IDE are common examples of busses
+where common Linux platforms will see such removal. Details of how drivers
+will notice and handle such removals are currently bus-specific, and often
+involve a separate thread.
-The methods to suspend and resume devices reside in struct bus_type:
-struct bus_type {
- ...
- int (*suspend)(struct device * dev, pm_message_t state);
- int (*resume)(struct device * dev);
-};
+Note that the bus-specific runtime PM wakeup mechanism can exist, and might
+be defined to share some of the same driver code as for system wakeup. For
+example, a bus-specific device driver's resume() method might be used there,
+so it wouldn't only be called from bus.resume() during system-wide wakeup.
+See bus-specific information about how runtime wakeup events are handled.
-Each bus driver is responsible implementing these methods, translating
-the call into a bus-specific request and forwarding the call to the
-bus-specific drivers. For example, PCI drivers implement suspend() and
-resume() methods in struct pci_driver. The PCI core is simply
-responsible for translating the pointers to PCI-specific ones and
-calling the low-level driver.
-
-This is done to a) ease transition to the new power management methods
-and leverage the existing PM code in various bus drivers; b) allow
-buses to implement generic and default PM routines for devices, and c)
-make the flow of execution obvious to the reader.
-
-
-System Power Management
-
-When the system enters a low-power state, the device tree is walked in
-a depth-first fashion to transition each device into a low-power
-state. The ordering of the device tree is guaranteed by the order in
-which devices get registered - children are never registered before
-their ancestors, and devices are placed at the back of the list when
-registered. By walking the list in reverse order, we are guaranteed to
-suspend devices in the proper order.
-
-Devices are suspended once with interrupts enabled. Drivers are
-expected to stop I/O transactions, save device state, and place the
-device into a low-power state. Drivers may sleep, allocate memory,
-etc. at will.
-
-Some devices are broken and will inevitably have problems powering
-down or disabling themselves with interrupts enabled. For these
-special cases, they may return -EAGAIN. This will put the device on a
-list to be taken care of later. When interrupts are disabled, before
-we enter the low-power state, their drivers are called again to put
-their device to sleep.
-
-On resume, the devices that returned -EAGAIN will be called to power
-themselves back on with interrupts disabled. Once interrupts have been
-re-enabled, the rest of the drivers will be called to resume their
-devices. On resume, a driver is responsible for powering back on each
-device, restoring state, and re-enabling I/O transactions for that
-device.
+System Devices
+--------------
System devices follow a slightly different API, which can be found in
include/linux/sysdev.h
drivers/base/sys.c
-System devices will only be suspended with interrupts disabled, and
-after all other devices have been suspended. On resume, they will be
-resumed before any other devices, and also with interrupts disabled.
+System devices will only be suspended with interrupts disabled, and after
+all other devices have been suspended. On resume, they will be resumed
+before any other devices, and also with interrupts disabled.
+That is, IRQs are disabled, the suspend_late() phase begins, then the
+sysdev_driver.suspend() phase, and the system enters a sleep state. Then
+the sysdev_driver.resume() phase begins, followed by the resume_early()
+phase, after which IRQs are enabled.
-Runtime Power Management
-
-Many devices are able to dynamically power down while the system is
-still running. This feature is useful for devices that are not being
-used, and can offer significant power savings on a running system.
-
-In each device's directory, there is a 'power' directory, which
-contains at least a 'state' file. Reading from this file displays what
-power state the device is currently in. Writing to this file initiates
-a transition to the specified power state, which must be a decimal in
-the range 1-3, inclusive; or 0 for 'On'.
+Code to actually enter and exit the system-wide low power state sometimes
+involves hardware details that are only known to the boot firmware, and
+may leave a CPU running software (from SRAM or flash memory) that monitors
+the system and manages its wakeup sequence.
-The PM core will call the ->suspend() method in the bus_type object
-that the device belongs to if the specified state is not 0, or
-->resume() if it is.
-Nothing will happen if the specified state is the same state the
-device is currently in.
-
-If the device is already in a low-power state, and the specified state
-is another, but different, low-power state, the ->resume() method will
-first be called to power the device back on, then ->suspend() will be
-called again with the new state.
-
-The driver is responsible for saving the working state of the device
-and putting it into the low-power state specified. If this was
-successful, it returns 0, and the device's power_state field is
-updated.
-
-The driver must take care to know whether or not it is able to
-properly resume the device, including all step of reinitialization
-necessary. (This is the hardest part, and the one most protected by
-NDA'd documents).
-
-The driver must also take care not to suspend a device that is
-currently in use. It is their responsibility to provide their own
-exclusion mechanisms.
-
-The runtime power transition happens with interrupts enabled. If a
-device cannot support being powered down with interrupts, it may
-return -EAGAIN (as it would during a system power management
-transition), but it will _not_ be called again, and the transaction
-will fail.
-
-There is currently no way to know what states a device or driver
-supports a priori. This will change in the future.
-
-pm_message_t meaning
-
-pm_message_t has two fields. event ("major"), and flags. If driver
-does not know event code, it aborts the request, returning error. Some
-drivers may need to deal with special cases based on the actual type
-of suspend operation being done at the system level. This is why
-there are flags.
-
-Event codes are:
-
-ON -- no need to do anything except special cases like broken
-HW.
-
-# NOTIFICATION -- pretty much same as ON?
-
-FREEZE -- stop DMA and interrupts, and be prepared to reinit HW from
-scratch. That probably means stop accepting upstream requests, the
-actual policy of what to do with them being specific to a given
-driver. It's acceptable for a network driver to just drop packets
-while a block driver is expected to block the queue so no request is
-lost. (Use IDE as an example on how to do that). FREEZE requires no
-power state change, and it's expected for drivers to be able to
-quickly transition back to operating state.
-
-SUSPEND -- like FREEZE, but also put hardware into low-power state. If
-there's need to distinguish several levels of sleep, additional flag
-is probably best way to do that.
-
-Transitions are only from a resumed state to a suspended state, never
-between 2 suspended states. (ON -> FREEZE or ON -> SUSPEND can happen,
-FREEZE -> SUSPEND or SUSPEND -> FREEZE can not).
-
-All events are:
-
-[NOTE NOTE NOTE: If you are driver author, you should not care; you
-should only look at event, and ignore flags.]
-
-#Prepare for suspend -- userland is still running but we are going to
-#enter suspend state. This gives drivers chance to load firmware from
-#disk and store it in memory, or do other activities taht require
-#operating userland, ability to kmalloc GFP_KERNEL, etc... All of these
-#are forbiden once the suspend dance is started.. event = ON, flags =
-#PREPARE_TO_SUSPEND
-
-Apm standby -- prepare for APM event. Quiesce devices to make life
-easier for APM BIOS. event = FREEZE, flags = APM_STANDBY
-
-Apm suspend -- same as APM_STANDBY, but it we should probably avoid
-spinning down disks. event = FREEZE, flags = APM_SUSPEND
-
-System halt, reboot -- quiesce devices to make life easier for BIOS. event
-= FREEZE, flags = SYSTEM_HALT or SYSTEM_REBOOT
-
-System shutdown -- at least disks need to be spun down, or data may be
-lost. Quiesce devices, just to make life easier for BIOS. event =
-FREEZE, flags = SYSTEM_SHUTDOWN
-
-Kexec -- turn off DMAs and put hardware into some state where new
-kernel can take over. event = FREEZE, flags = KEXEC
-
-Powerdown at end of swsusp -- very similar to SYSTEM_SHUTDOWN, except wake
-may need to be enabled on some devices. This actually has at least 3
-subtypes, system can reboot, enter S4 and enter S5 at the end of
-swsusp. event = FREEZE, flags = SWSUSP and one of SYSTEM_REBOOT,
-SYSTEM_SHUTDOWN, SYSTEM_S4
-
-Suspend to ram -- put devices into low power state. event = SUSPEND,
-flags = SUSPEND_TO_RAM
-
-Freeze for swsusp snapshot -- stop DMA and interrupts. No need to put
-devices into low power mode, but you must be able to reinitialize
-device from scratch in resume method. This has two flavors, its done
-once on suspending kernel, once on resuming kernel. event = FREEZE,
-flags = DURING_SUSPEND or DURING_RESUME
-
-Device detach requested from /sys -- deinitialize device; proably same as
-SYSTEM_SHUTDOWN, I do not understand this one too much. probably event
-= FREEZE, flags = DEV_DETACH.
-
-#These are not really events sent:
-#
-#System fully on -- device is working normally; this is probably never
-#passed to suspend() method... event = ON, flags = 0
-#
-#Ready after resume -- userland is now running, again. Time to free any
-#memory you ate during prepare to suspend... event = ON, flags =
-#READY_AFTER_RESUME
-#
+Runtime Power Management
+========================
+Many devices are able to dynamically power down while the system is still
+running. This feature is useful for devices that are not being used, and
+can offer significant power savings on a running system. These devices
+often support a range of runtime power states, which might use names such
+as "off", "sleep", "idle", "active", and so on. Those states will in some
+cases (like PCI) be partially constrained by a bus the device uses, and will
+usually include hardware states that are also used in system sleep states.
+
+However, note that if a driver puts a device into a runtime low power state
+and the system then goes into a system-wide sleep state, it normally ought
+to resume into that runtime low power state rather than "full on". Such
+distinctions would be part of the driver-internal state machine for that
+hardware; the whole point of runtime power management is to be sure that
+drivers are decoupled in that way from the state machine governing phases
+of the system-wide power/sleep state transitions.
+
+
+Power Saving Techniques
+-----------------------
+Normally runtime power management is handled by the drivers without specific
+userspace or kernel intervention, by device-aware use of techniques like:
+
+ Using information provided by other system layers
+ - stay deeply "off" except between open() and close()
+ - if transceiver/PHY indicates "nobody connected", stay "off"
+ - application protocols may include power commands or hints
+
+ Using fewer CPU cycles
+ - using DMA instead of PIO
+ - removing timers, or making them lower frequency
+ - shortening "hot" code paths
+ - eliminating cache misses
+ - (sometimes) offloading work to device firmware
+
+ Reducing other resource costs
+ - gating off unused clocks in software (or hardware)
+ - switching off unused power supplies
+ - eliminating (or delaying/merging) IRQs
+ - tuning DMA to use word and/or burst modes
+
+ Using device-specific low power states
+ - using lower voltages
+ - avoiding needless DMA transfers
+
+Read your hardware documentation carefully to see the opportunities that
+may be available. If you can, measure the actual power usage and check
+it against the budget established for your project.
+
+
+Examples: USB hosts, system timer, system CPU
+----------------------------------------------
+USB host controllers make interesting, if complex, examples. In many cases
+these have no work to do: no USB devices are connected, or all of them are
+in the USB "suspend" state. Linux host controller drivers can then disable
+periodic DMA transfers that would otherwise be a constant power drain on the
+memory subsystem, and enter a suspend state. In power-aware controllers,
+entering that suspend state may disable the clock used with USB signaling,
+saving a certain amount of power.
+
+The controller will be woken from that state (with an IRQ) by changes to the
+signal state on the data lines of a given port, for example by an existing
+peripheral requesting "remote wakeup" or by plugging a new peripheral. The
+same wakeup mechanism usually works from "standby" sleep states, and on some
+systems also from "suspend to RAM" (or even "suspend to disk") states.
+(Except that ACPI may be involved instead of normal IRQs, on some hardware.)
+
+System devices like timers and CPUs may have special roles in the platform
+power management scheme. For example, system timers using a "dynamic tick"
+approach don't just save CPU cycles (by eliminating needless timer IRQs),
+but they may also open the door to using lower power CPU "idle" states that
+cost more than a jiffie to enter and exit. On x86 systems these are states
+like "C3"; note that periodic DMA transfers from a USB host controller will
+also prevent entry to a C3 state, much like a periodic timer IRQ.
+
+That kind of runtime mechanism interaction is common. "System On Chip" (SOC)
+processors often have low power idle modes that can't be entered unless
+certain medium-speed clocks (often 12 or 48 MHz) are gated off. When the
+drivers gate those clocks effectively, then the system idle task may be able
+to use the lower power idle modes and thereby increase battery life.
+
+If the CPU can have a "cpufreq" driver, there also may be opportunities
+to shift to lower voltage settings and reduce the power cost of executing
+a given number of instructions. (Without voltage adjustment, it's rare
+for cpufreq to save much power; the cost-per-instruction must go down.)
+
+
+/sys/devices/.../power/state files
+==================================
+For now you can also test some of this functionality using sysfs.
+
+ DEPRECATED: USE "power/state" ONLY FOR DRIVER TESTING, AND
+ AVOID USING dev->power.power_state IN DRIVERS.
+
+ THESE WILL BE REMOVED. IF THE "power/state" FILE GETS REPLACED,
+ IT WILL BECOME SOMETHING COUPLED TO THE BUS OR DRIVER.
+
+In each device's directory, there is a 'power' directory, which contains
+at least a 'state' file. The value of this field is effectively boolean,
+PM_EVENT_ON or PM_EVENT_SUSPEND.
+
+ * Reading from this file displays a value corresponding to
+ the power.power_state.event field. All nonzero values are
+ displayed as "2", corresponding to a low power state; zero
+ is displayed as "0", corresponding to normal operation.
+
+ * Writing to this file initiates a transition using the
+ specified event code number; only '0', '2', and '3' are
+ accepted (without a newline); '2' and '3' are both
+ mapped to PM_EVENT_SUSPEND.
+
+On writes, the PM core relies on that recorded event code and the device/bus
+capabilities to determine whether it uses a partial suspend() or resume()
+sequence to change things so that the recorded event corresponds to the
+numeric parameter.
+
+ - If the bus requires the irqs-disabled suspend_late()/resume_early()
+ phases, writes fail because those operations are not supported here.
+
+ - If the recorded value is the expected value, nothing is done.
+
+ - If the recorded value is nonzero, the device is partially resumed,
+ using the bus.resume() and/or class.resume() methods.
+
+ - If the target value is nonzero, the device is partially suspended,
+ using the class.suspend() and/or bus.suspend() methods and the
+ PM_EVENT_SUSPEND message.
+
+Drivers have no way to tell whether their suspend() and resume() calls
+have come through the sysfs power/state file or as part of entering a
+system sleep state, except that when accessed through sysfs the normal
+parent/child sequencing rules are ignored. Drivers (such as bus, bridge,
+or hub drivers) which expose child devices may need to enforce those rules
+on their own.
extern int attribute_container_init(void);
extern int bus_add_device(struct device * dev);
-extern void bus_attach_device(struct device * dev);
+extern int bus_attach_device(struct device * dev);
extern void bus_remove_device(struct device * dev);
extern struct bus_type *get_bus(struct bus_type * bus);
extern void put_bus(struct bus_type * bus);
if (bus) {
pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id);
error = device_add_attrs(bus, dev);
- if (!error) {
- sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id);
- sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "subsystem");
- sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus");
- }
+ if (error)
+ goto out;
+ error = sysfs_create_link(&bus->devices.kobj,
+ &dev->kobj, dev->bus_id);
+ if (error)
+ goto out;
+ error = sysfs_create_link(&dev->kobj,
+ &dev->bus->subsys.kset.kobj, "subsystem");
+ if (error)
+ goto out;
+ error = sysfs_create_link(&dev->kobj,
+ &dev->bus->subsys.kset.kobj, "bus");
}
+out:
return error;
}
* bus_attach_device - add device to bus
* @dev: device tried to attach to a driver
*
+ * - Add device to bus's list of devices.
* - Try to attach to driver.
*/
-void bus_attach_device(struct device * dev)
+int bus_attach_device(struct device * dev)
{
- struct bus_type * bus = dev->bus;
+ struct bus_type *bus = dev->bus;
+ int ret = 0;
if (bus) {
- device_attach(dev);
- klist_add_tail(&dev->knode_bus, &bus->klist_devices);
+ dev->is_registered = 1;
+ ret = device_attach(dev);
+ if (ret >= 0) {
+ klist_add_tail(&dev->knode_bus, &bus->klist_devices);
+ ret = 0;
+ } else
+ dev->is_registered = 0;
}
+ return ret;
}
/**
sysfs_remove_link(&dev->kobj, "bus");
sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id);
device_remove_attrs(dev->bus, dev);
- klist_remove(&dev->knode_bus);
+ dev->is_registered = 0;
+ klist_del(&dev->knode_bus);
pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id);
device_release_driver(dev);
put_bus(dev->bus);
* Thanks to drivers making their tables __devinit, we can't allow manual
* bind and unbind from userspace unless CONFIG_HOTPLUG is enabled.
*/
-static void add_bind_files(struct device_driver *drv)
+static int __must_check add_bind_files(struct device_driver *drv)
{
- driver_create_file(drv, &driver_attr_unbind);
- driver_create_file(drv, &driver_attr_bind);
+ int ret;
+
+ ret = driver_create_file(drv, &driver_attr_unbind);
+ if (ret == 0) {
+ ret = driver_create_file(drv, &driver_attr_bind);
+ if (ret)
+ driver_remove_file(drv, &driver_attr_unbind);
+ }
+ return ret;
}
static void remove_bind_files(struct device_driver *drv)
driver_remove_file(drv, &driver_attr_unbind);
}
#else
-static inline void add_bind_files(struct device_driver *drv) {}
+static inline int add_bind_files(struct device_driver *drv) { return 0; }
static inline void remove_bind_files(struct device_driver *drv) {}
#endif
* @drv: driver.
*
*/
-int bus_add_driver(struct device_driver * drv)
+int bus_add_driver(struct device_driver *drv)
{
struct bus_type * bus = get_bus(drv->bus);
int error = 0;
if (bus) {
pr_debug("bus %s: add driver %s\n", bus->name, drv->name);
error = kobject_set_name(&drv->kobj, "%s", drv->name);
- if (error) {
- put_bus(bus);
- return error;
- }
+ if (error)
+ goto out_put_bus;
drv->kobj.kset = &bus->drivers;
- if ((error = kobject_register(&drv->kobj))) {
- put_bus(bus);
- return error;
- }
+ if ((error = kobject_register(&drv->kobj)))
+ goto out_put_bus;
- driver_attach(drv);
+ error = driver_attach(drv);
+ if (error)
+ goto out_unregister;
klist_add_tail(&drv->knode_bus, &bus->klist_drivers);
module_add_driver(drv->owner, drv);
- driver_add_attrs(bus, drv);
- add_bind_files(drv);
+ error = driver_add_attrs(bus, drv);
+ if (error) {
+ /* How the hell do we get out of this pickle? Give up */
+ printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n",
+ __FUNCTION__, drv->name);
+ }
+ error = add_bind_files(drv);
+ if (error) {
+ /* Ditto */
+ printk(KERN_ERR "%s: add_bind_files(%s) failed\n",
+ __FUNCTION__, drv->name);
+ }
}
return error;
+out_unregister:
+ kobject_unregister(&drv->kobj);
+out_put_bus:
+ put_bus(bus);
+ return error;
}
-
/**
* bus_remove_driver - delete driver from bus's knowledge.
* @drv: driver.
/* Helper for bus_rescan_devices's iter */
-static int bus_rescan_devices_helper(struct device *dev, void *data)
+static int __must_check bus_rescan_devices_helper(struct device *dev,
+ void *data)
{
+ int ret = 0;
+
if (!dev->driver) {
if (dev->parent) /* Needed for USB */
down(&dev->parent->sem);
- device_attach(dev);
+ ret = device_attach(dev);
if (dev->parent)
up(&dev->parent->sem);
+ if (ret > 0)
+ ret = 0;
}
- return 0;
+ return ret < 0 ? ret : 0;
}
/**
* attached and rescan it against existing drivers to see if it matches
* any by calling device_attach() for the unbound devices.
*/
-void bus_rescan_devices(struct bus_type * bus)
+int bus_rescan_devices(struct bus_type * bus)
{
- bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
+ return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
}
/**
* to use if probing criteria changed during a devices lifetime and
* driver attachment should change accordingly.
*/
-void device_reprobe(struct device *dev)
+int device_reprobe(struct device *dev)
{
if (dev->driver) {
if (dev->parent) /* Needed for USB */
if (dev->parent)
up(&dev->parent->sem);
}
-
- bus_rescan_devices_helper(dev, NULL);
+ return bus_rescan_devices_helper(dev, NULL);
}
EXPORT_SYMBOL_GPL(device_reprobe);
-struct bus_type * get_bus(struct bus_type * bus)
+struct bus_type *get_bus(struct bus_type *bus)
{
- return bus ? container_of(subsys_get(&bus->subsys), struct bus_type, subsys) : NULL;
+ return bus ? container_of(subsys_get(&bus->subsys),
+ struct bus_type, subsys) : NULL;
}
void put_bus(struct bus_type * bus)
put_device(dev);
}
-static void klist_drivers_get(struct klist_node *n)
-{
- struct device_driver *drv = container_of(n, struct device_driver,
- knode_bus);
-
- get_driver(drv);
-}
-
-static void klist_drivers_put(struct klist_node *n)
-{
- struct device_driver *drv = container_of(n, struct device_driver,
- knode_bus);
-
- put_driver(drv);
-}
-
/**
* bus_register - register a bus with the system.
* @bus: bus.
goto bus_drivers_fail;
klist_init(&bus->klist_devices, klist_devices_get, klist_devices_put);
- klist_init(&bus->klist_drivers, klist_drivers_get, klist_drivers_put);
+ klist_init(&bus->klist_drivers, NULL, NULL);
bus_add_attrs(bus);
pr_debug("bus type '%s' registered\n", bus->name);
#include <linux/slab.h>
#include "base.h"
+extern struct subsystem devices_subsys;
+
#define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr)
#define to_class(obj) container_of(obj, struct class, subsys.kset.kobj)
* Note, the pointer created here is to be destroyed when finished by
* making a call to class_destroy().
*/
-struct class *class_create(struct module *owner, char *name)
+struct class *class_create(struct module *owner, const char *name)
{
struct class *cls;
int retval;
pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
if (class_dev->dev) {
- /* add physical device, backing this device */
+ /* add device, backing this class device (deprecated) */
struct device *dev = class_dev->dev;
char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);
struct class_device *class_device_create(struct class *cls,
struct class_device *parent,
dev_t devt,
- struct device *device, char *fmt, ...)
+ struct device *device,
+ const char *fmt, ...)
{
va_list args;
struct class_device *class_dev = NULL;
{
struct class *parent;
struct class_device *class_dev;
+ struct device *dev;
if (!class_intf || !class_intf->class)
return -ENODEV;
list_for_each_entry(class_dev, &parent->children, node)
class_intf->add(class_dev, class_intf);
}
+ if (class_intf->add_dev) {
+ list_for_each_entry(dev, &parent->devices, node)
+ class_intf->add_dev(dev, class_intf);
+ }
up(&parent->sem);
return 0;
{
struct class * parent = class_intf->class;
struct class_device *class_dev;
+ struct device *dev;
if (!parent)
return;
list_for_each_entry(class_dev, &parent->children, node)
class_intf->remove(class_dev, class_intf);
}
+ if (class_intf->remove_dev) {
+ list_for_each_entry(dev, &parent->devices, node)
+ class_intf->remove_dev(dev, class_intf);
+ }
up(&parent->sem);
class_put(parent);
}
+int virtual_device_parent(struct device *dev)
+{
+ if (!dev->class)
+ return -ENODEV;
+
+ if (!dev->class->virtual_dir) {
+ static struct kobject *virtual_dir = NULL;
+
+ if (!virtual_dir)
+ virtual_dir = kobject_add_dir(&devices_subsys.kset.kobj, "virtual");
+ dev->class->virtual_dir = kobject_add_dir(virtual_dir, dev->class->name);
+ }
+ dev->kobj.parent = dev->class->virtual_dir;
+ return 0;
+}
int __init classes_init(void)
{
*
* Copyright (c) 2002-3 Patrick Mochel
* Copyright (c) 2002-3 Open Source Development Labs
+ * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
+ * Copyright (c) 2006 Novell, Inc.
*
* This file is released under the GPLv2
*
if (dev->release)
dev->release(dev);
+ else if (dev->class && dev->class->dev_release)
+ dev->class->dev_release(dev);
else {
printk(KERN_ERR "Device '%s' does not have a release() function, "
"it is broken and must be fixed.\n",
"MINOR=%u", MINOR(dev->devt));
}
- /* add bus name of physical device */
+ /* add bus name (same as SUBSYSTEM, deprecated) */
if (dev->bus)
add_uevent_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"PHYSDEVBUS=%s", dev->bus->name);
- /* add driver name of physical device */
- if (dev->driver)
+ /* add driver name (PHYSDEV* values are deprecated)*/
+ if (dev->driver) {
+ add_uevent_var(envp, num_envp, &i,
+ buffer, buffer_size, &length,
+ "DRIVER=%s", dev->driver->name);
add_uevent_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"PHYSDEVDRIVER=%s", dev->driver->name);
+ }
/* terminate, set to next free slot, shrink available space */
envp[i] = NULL;
}
}
+ if (dev->class && dev->class->dev_uevent) {
+ /* have the class specific function add its stuff */
+ retval = dev->class->dev_uevent(dev, envp, num_envp, buffer, buffer_size);
+ if (retval) {
+ pr_debug("%s - dev_uevent() returned %d\n",
+ __FUNCTION__, retval);
+ }
+ }
+
return retval;
}
return count;
}
+static int device_add_groups(struct device *dev)
+{
+ int i;
+ int error = 0;
+
+ if (dev->groups) {
+ for (i = 0; dev->groups[i]; i++) {
+ error = sysfs_create_group(&dev->kobj, dev->groups[i]);
+ if (error) {
+ while (--i >= 0)
+ sysfs_remove_group(&dev->kobj, dev->groups[i]);
+ goto out;
+ }
+ }
+ }
+out:
+ return error;
+}
+
+static void device_remove_groups(struct device *dev)
+{
+ int i;
+ if (dev->groups) {
+ for (i = 0; dev->groups[i]; i++) {
+ sysfs_remove_group(&dev->kobj, dev->groups[i]);
+ }
+ }
+}
+
+static int device_add_attrs(struct device *dev)
+{
+ struct class *class = dev->class;
+ int error = 0;
+ int i;
+
+ if (!class)
+ return 0;
+
+ if (class->dev_attrs) {
+ for (i = 0; attr_name(class->dev_attrs[i]); i++) {
+ error = device_create_file(dev, &class->dev_attrs[i]);
+ if (error)
+ break;
+ }
+ }
+ if (error)
+ while (--i >= 0)
+ device_remove_file(dev, &class->dev_attrs[i]);
+ return error;
+}
+
+static void device_remove_attrs(struct device *dev)
+{
+ struct class *class = dev->class;
+ int i;
+
+ if (!class)
+ return;
+
+ if (class->dev_attrs) {
+ for (i = 0; attr_name(class->dev_attrs[i]); i++)
+ device_remove_file(dev, &class->dev_attrs[i]);
+ }
+}
+
+
static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
char *buf)
{
}
}
+/**
+ * device_create_bin_file - create sysfs binary attribute file for device.
+ * @dev: device.
+ * @attr: device binary attribute descriptor.
+ */
+int device_create_bin_file(struct device *dev, struct bin_attribute *attr)
+{
+ int error = -EINVAL;
+ if (dev)
+ error = sysfs_create_bin_file(&dev->kobj, attr);
+ return error;
+}
+EXPORT_SYMBOL_GPL(device_create_bin_file);
+
+/**
+ * device_remove_bin_file - remove sysfs binary attribute file
+ * @dev: device.
+ * @attr: device binary attribute descriptor.
+ */
+void device_remove_bin_file(struct device *dev, struct bin_attribute *attr)
+{
+ if (dev)
+ sysfs_remove_bin_file(&dev->kobj, attr);
+}
+EXPORT_SYMBOL_GPL(device_remove_bin_file);
+
static void klist_children_get(struct klist_node *n)
{
struct device *dev = container_of(n, struct device, knode_parent);
{
struct device *parent = NULL;
char *class_name = NULL;
+ struct class_interface *class_intf;
int error = -EINVAL;
dev = get_device(dev);
if (!dev || !strlen(dev->bus_id))
goto Error;
+ /* if this is a class device, and has no parent, create one */
+ if ((dev->class) && (dev->parent == NULL)) {
+ error = virtual_device_parent(dev);
+ if (error)
+ goto Error;
+ }
+
parent = get_device(dev->parent);
pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id);
if ((error = kobject_add(&dev->kobj)))
goto Error;
+ /* notify platform of device entry */
+ if (platform_notify)
+ platform_notify(dev);
+
dev->uevent_attr.attr.name = "uevent";
dev->uevent_attr.attr.mode = S_IWUSR;
if (dev->driver)
"subsystem");
sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj,
dev->bus_id);
-
- sysfs_create_link(&dev->kobj, &dev->parent->kobj, "device");
- class_name = make_class_name(dev->class->name, &dev->kobj);
- sysfs_create_link(&dev->parent->kobj, &dev->kobj, class_name);
+ if (parent) {
+ sysfs_create_link(&dev->kobj, &dev->parent->kobj, "device");
+ class_name = make_class_name(dev->class->name, &dev->kobj);
+ sysfs_create_link(&dev->parent->kobj, &dev->kobj, class_name);
+ }
}
+ if ((error = device_add_attrs(dev)))
+ goto AttrsError;
+ if ((error = device_add_groups(dev)))
+ goto GroupError;
if ((error = device_pm_add(dev)))
goto PMError;
if ((error = bus_add_device(dev)))
klist_add_tail(&dev->knode_parent, &parent->klist_children);
if (dev->class) {
- /* tie the class to the device */
down(&dev->class->sem);
+ /* tie the class to the device */
list_add_tail(&dev->node, &dev->class->devices);
+
+ /* notify any interfaces that the device is here */
+ list_for_each_entry(class_intf, &dev->class->interfaces, node)
+ if (class_intf->add_dev)
+ class_intf->add_dev(dev, class_intf);
up(&dev->class->sem);
}
-
- /* notify platform of device entry */
- if (platform_notify)
- platform_notify(dev);
Done:
kfree(class_name);
put_device(dev);
BusError:
device_pm_remove(dev);
PMError:
+ device_remove_groups(dev);
+ GroupError:
+ device_remove_attrs(dev);
+ AttrsError:
if (dev->devt_attr) {
device_remove_file(dev, dev->devt_attr);
kfree(dev->devt_attr);
{
struct device * parent = dev->parent;
char *class_name = NULL;
+ struct class_interface *class_intf;
if (parent)
klist_del(&dev->knode_parent);
sysfs_remove_link(&dev->kobj, "subsystem");
sysfs_remove_link(&dev->class->subsys.kset.kobj, dev->bus_id);
class_name = make_class_name(dev->class->name, &dev->kobj);
- sysfs_remove_link(&dev->kobj, "device");
- sysfs_remove_link(&dev->parent->kobj, class_name);
+ if (parent) {
+ sysfs_remove_link(&dev->kobj, "device");
+ sysfs_remove_link(&dev->parent->kobj, class_name);
+ }
kfree(class_name);
down(&dev->class->sem);
+ /* notify any interfaces that the device is now gone */
+ list_for_each_entry(class_intf, &dev->class->interfaces, node)
+ if (class_intf->remove_dev)
+ class_intf->remove_dev(dev, class_intf);
+ /* remove the device from the class list */
list_del_init(&dev->node);
up(&dev->class->sem);
}
device_remove_file(dev, &dev->uevent_attr);
+ device_remove_groups(dev);
+ device_remove_attrs(dev);
/* Notify the platform of the removal, in case they
* need to do anything...
* been created with a call to class_create().
*/
struct device *device_create(struct class *class, struct device *parent,
- dev_t devt, char *fmt, ...)
+ dev_t devt, const char *fmt, ...)
{
va_list args;
struct device *dev = NULL;
if (class == NULL || IS_ERR(class))
goto error;
- if (parent == NULL) {
- printk(KERN_WARNING "%s does not work yet for NULL parents\n", __FUNCTION__);
- goto error;
- }
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev) {
device_unregister(dev);
}
EXPORT_SYMBOL_GPL(device_destroy);
+
+/**
+ * device_rename - renames a device
+ * @dev: the pointer to the struct device to be renamed
+ * @new_name: the new name of the device
+ */
+int device_rename(struct device *dev, char *new_name)
+{
+ char *old_class_name = NULL;
+ char *new_class_name = NULL;
+ char *old_symlink_name = NULL;
+ int error;
+
+ dev = get_device(dev);
+ if (!dev)
+ return -EINVAL;
+
+ pr_debug("DEVICE: renaming '%s' to '%s'\n", dev->bus_id, new_name);
+
+ if ((dev->class) && (dev->parent))
+ old_class_name = make_class_name(dev->class->name, &dev->kobj);
+
+ if (dev->class) {
+ old_symlink_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
+ if (!old_symlink_name)
+ return -ENOMEM;
+ strlcpy(old_symlink_name, dev->bus_id, BUS_ID_SIZE);
+ }
+
+ strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);
+
+ error = kobject_rename(&dev->kobj, new_name);
+
+ if (old_class_name) {
+ new_class_name = make_class_name(dev->class->name, &dev->kobj);
+ if (new_class_name) {
+ sysfs_create_link(&dev->parent->kobj, &dev->kobj,
+ new_class_name);
+ sysfs_remove_link(&dev->parent->kobj, old_class_name);
+ }
+ }
+ if (dev->class) {
+ sysfs_remove_link(&dev->class->subsys.kset.kobj,
+ old_symlink_name);
+ sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj,
+ dev->bus_id);
+ }
+ put_device(dev);
+
+ kfree(old_class_name);
+ kfree(new_class_name);
+ kfree(old_symlink_name);
+
+ return error;
+}
#include <linux/device.h>
#include <linux/module.h>
+#include <linux/kthread.h>
#include "base.h"
#include "power/power.h"
*
* This function must be called with @dev->sem held.
*/
-void device_bind_driver(struct device * dev)
+int device_bind_driver(struct device *dev)
{
- if (klist_node_attached(&dev->knode_driver))
- return;
+ int ret;
+
+ if (klist_node_attached(&dev->knode_driver)) {
+ printk(KERN_WARNING "%s: device %s already bound\n",
+ __FUNCTION__, kobject_name(&dev->kobj));
+ return 0;
+ }
pr_debug("bound device '%s' to driver '%s'\n",
dev->bus_id, dev->driver->name);
klist_add_tail(&dev->knode_driver, &dev->driver->klist_devices);
- sysfs_create_link(&dev->driver->kobj, &dev->kobj,
+ ret = sysfs_create_link(&dev->driver->kobj, &dev->kobj,
kobject_name(&dev->kobj));
- sysfs_create_link(&dev->kobj, &dev->driver->kobj, "driver");
+ if (ret == 0) {
+ ret = sysfs_create_link(&dev->kobj, &dev->driver->kobj,
+ "driver");
+ if (ret)
+ sysfs_remove_link(&dev->driver->kobj,
+ kobject_name(&dev->kobj));
+ }
+ return ret;
}
-/**
- * driver_probe_device - attempt to bind device & driver.
- * @drv: driver.
- * @dev: device.
- *
- * First, we call the bus's match function, if one present, which
- * should compare the device IDs the driver supports with the
- * device IDs of the device. Note we don't do this ourselves
- * because we don't know the format of the ID structures, nor what
- * is to be considered a match and what is not.
- *
- * This function returns 1 if a match is found, an error if one
- * occurs (that is not -ENODEV or -ENXIO), and 0 otherwise.
- *
- * This function must be called with @dev->sem held. When called
- * for a USB interface, @dev->parent->sem must be held as well.
- */
-int driver_probe_device(struct device_driver * drv, struct device * dev)
+struct stupid_thread_structure {
+ struct device_driver *drv;
+ struct device *dev;
+};
+
+static atomic_t probe_count = ATOMIC_INIT(0);
+static int really_probe(void *void_data)
{
+ struct stupid_thread_structure *data = void_data;
+ struct device_driver *drv = data->drv;
+ struct device *dev = data->dev;
int ret = 0;
- if (drv->bus->match && !drv->bus->match(dev, drv))
- goto Done;
+ atomic_inc(&probe_count);
+ pr_debug("%s: Probing driver %s with device %s\n",
+ drv->bus->name, drv->name, dev->bus_id);
- pr_debug("%s: Matched Device %s with Driver %s\n",
- drv->bus->name, dev->bus_id, drv->name);
dev->driver = drv;
if (dev->bus->probe) {
ret = dev->bus->probe(dev);
if (ret) {
dev->driver = NULL;
- goto ProbeFailed;
+ goto probe_failed;
}
} else if (drv->probe) {
ret = drv->probe(dev);
if (ret) {
dev->driver = NULL;
- goto ProbeFailed;
+ goto probe_failed;
}
}
- device_bind_driver(dev);
+ if (device_bind_driver(dev)) {
+ printk(KERN_ERR "%s: device_bind_driver(%s) failed\n",
+ __FUNCTION__, dev->bus_id);
+ /* How does undo a ->probe? We're screwed. */
+ }
ret = 1;
pr_debug("%s: Bound Device %s to Driver %s\n",
drv->bus->name, dev->bus_id, drv->name);
- goto Done;
+ goto done;
- ProbeFailed:
+probe_failed:
if (ret == -ENODEV || ret == -ENXIO) {
/* Driver matched, but didn't support device
* or device not found.
"%s: probe of %s failed with error %d\n",
drv->name, dev->bus_id, ret);
}
- Done:
+done:
+ kfree(data);
+ atomic_dec(&probe_count);
+ return ret;
+}
+
+/**
+ * driver_probe_done
+ * Determine if the probe sequence is finished or not.
+ *
+ * Should somehow figure out how to use a semaphore, not an atomic variable...
+ */
+int driver_probe_done(void)
+{
+ pr_debug("%s: probe_count = %d\n", __FUNCTION__,
+ atomic_read(&probe_count));
+ if (atomic_read(&probe_count))
+ return -EBUSY;
+ return 0;
+}
+
+/**
+ * driver_probe_device - attempt to bind device & driver together
+ * @drv: driver to bind a device to
+ * @dev: device to try to bind to the driver
+ *
+ * First, we call the bus's match function, if one present, which should
+ * compare the device IDs the driver supports with the device IDs of the
+ * device. Note we don't do this ourselves because we don't know the
+ * format of the ID structures, nor what is to be considered a match and
+ * what is not.
+ *
+ * This function returns 1 if a match is found, an error if one occurs
+ * (that is not -ENODEV or -ENXIO), and 0 otherwise.
+ *
+ * This function must be called with @dev->sem held. When called for a
+ * USB interface, @dev->parent->sem must be held as well.
+ */
+int driver_probe_device(struct device_driver * drv, struct device * dev)
+{
+ struct stupid_thread_structure *data;
+ struct task_struct *probe_task;
+ int ret = 0;
+
+ if (!device_is_registered(dev))
+ return -ENODEV;
+ if (drv->bus->match && !drv->bus->match(dev, drv))
+ goto done;
+
+ pr_debug("%s: Matched Device %s with Driver %s\n",
+ drv->bus->name, dev->bus_id, drv->name);
+
+ data = kmalloc(sizeof(*data), GFP_KERNEL);
+ data->drv = drv;
+ data->dev = dev;
+
+ if (drv->multithread_probe) {
+ probe_task = kthread_run(really_probe, data,
+ "probe-%s", dev->bus_id);
+ if (IS_ERR(probe_task))
+ ret = PTR_ERR(probe_task);
+ } else
+ ret = really_probe(data);
+
+done:
return ret;
}
down(&dev->sem);
if (dev->driver) {
- device_bind_driver(dev);
- ret = 1;
+ ret = device_bind_driver(dev);
+ if (ret == 0)
+ ret = 1;
} else
ret = bus_for_each_drv(dev->bus, NULL, dev, __device_attach);
up(&dev->sem);
* returns 0 and the @dev->driver is set, we've found a
* compatible pair.
*/
-void driver_attach(struct device_driver * drv)
+int driver_attach(struct device_driver * drv)
{
- bus_for_each_dev(drv->bus, NULL, drv, __driver_attach);
+ return bus_for_each_dev(drv->bus, NULL, drv, __driver_attach);
}
/**
kobject_put(&drv->kobj);
}
-static void klist_devices_get(struct klist_node *n)
-{
- struct device *dev = container_of(n, struct device, knode_driver);
-
- get_device(dev);
-}
-
-static void klist_devices_put(struct klist_node *n)
-{
- struct device *dev = container_of(n, struct device, knode_driver);
-
- put_device(dev);
-}
-
/**
* driver_register - register driver with bus
* @drv: driver to register
(drv->bus->shutdown && drv->shutdown)) {
printk(KERN_WARNING "Driver '%s' needs updating - please use bus_type methods\n", drv->name);
}
- klist_init(&drv->klist_devices, klist_devices_get, klist_devices_put);
+ klist_init(&drv->klist_devices, NULL, NULL);
init_completion(&drv->unloaded);
return bus_add_driver(drv);
}
return (strncmp(pdev->name, drv->name, BUS_ID_SIZE) == 0);
}
-static int platform_suspend(struct device * dev, pm_message_t state)
+static int platform_suspend(struct device *dev, pm_message_t mesg)
{
int ret = 0;
if (dev->driver && dev->driver->suspend)
- ret = dev->driver->suspend(dev, state);
+ ret = dev->driver->suspend(dev, mesg);
+
+ return ret;
+}
+
+static int platform_suspend_late(struct device *dev, pm_message_t mesg)
+{
+ struct platform_driver *drv = to_platform_driver(dev->driver);
+ struct platform_device *pdev = container_of(dev, struct platform_device, dev);
+ int ret = 0;
+
+ if (dev->driver && drv->suspend_late)
+ ret = drv->suspend_late(pdev, mesg);
+
+ return ret;
+}
+
+static int platform_resume_early(struct device *dev)
+{
+ struct platform_driver *drv = to_platform_driver(dev->driver);
+ struct platform_device *pdev = container_of(dev, struct platform_device, dev);
+ int ret = 0;
+
+ if (dev->driver && drv->resume_early)
+ ret = drv->resume_early(pdev);
return ret;
}
.match = platform_match,
.uevent = platform_uevent,
.suspend = platform_suspend,
+ .suspend_late = platform_suspend_late,
+ .resume_early = platform_resume_early,
.resume = platform_resume,
};
EXPORT_SYMBOL_GPL(platform_bus_type);
dev_dbg(dev,"resuming\n");
error = dev->bus->resume(dev);
}
+ if (dev->class && dev->class->resume) {
+ dev_dbg(dev,"class resume\n");
+ error = dev->class->resume(dev);
+ }
up(&dev->sem);
TRACE_RESUME(error);
return error;
}
+static int resume_device_early(struct device * dev)
+{
+ int error = 0;
+ TRACE_DEVICE(dev);
+ TRACE_RESUME(0);
+ if (dev->bus && dev->bus->resume_early) {
+ dev_dbg(dev,"EARLY resume\n");
+ error = dev->bus->resume_early(dev);
+ }
+ TRACE_RESUME(error);
+ return error;
+}
+
+/*
+ * Resume the devices that have either not gone through
+ * the late suspend, or that did go through it but also
+ * went through the early resume
+ */
void dpm_resume(void)
{
down(&dpm_list_sem);
void device_resume(void)
{
+ might_sleep();
down(&dpm_sem);
dpm_resume();
up(&dpm_sem);
/**
- * device_power_up_irq - Power on some devices.
+ * dpm_power_up - Power on some devices.
*
* Walk the dpm_off_irq list and power each device up. This
* is used for devices that required they be powered down with
- * interrupts disabled. As devices are powered on, they are moved to
- * the dpm_suspended list.
+ * interrupts disabled. As devices are powered on, they are moved
+ * to the dpm_active list.
*
* Interrupts must be disabled when calling this.
*/
struct list_head * entry = dpm_off_irq.next;
struct device * dev = to_device(entry);
- get_device(dev);
- list_move_tail(entry, &dpm_active);
- resume_device(dev);
- put_device(dev);
+ list_move_tail(entry, &dpm_off);
+ resume_device_early(dev);
}
}
/**
- * device_pm_power_up - Turn on all devices that need special attention.
+ * device_power_up - Turn on all devices that need special attention.
*
* Power on system devices then devices that required we shut them down
* with interrupts disabled.
switch (event) {
case PM_EVENT_SUSPEND: return "suspend";
case PM_EVENT_FREEZE: return "freeze";
+ case PM_EVENT_PRETHAW: return "prethaw";
default: return "(unknown suspend event)";
}
}
dev->power.prev_state = dev->power.power_state;
- if (dev->bus && dev->bus->suspend && !dev->power.power_state.event) {
+ if (dev->class && dev->class->suspend && !dev->power.power_state.event) {
+ dev_dbg(dev, "class %s%s\n",
+ suspend_verb(state.event),
+ ((state.event == PM_EVENT_SUSPEND)
+ && device_may_wakeup(dev))
+ ? ", may wakeup"
+ : ""
+ );
+ error = dev->class->suspend(dev, state);
+ suspend_report_result(dev->class->suspend, error);
+ }
+
+ if (!error && dev->bus && dev->bus->suspend && !dev->power.power_state.event) {
dev_dbg(dev, "%s%s\n",
suspend_verb(state.event),
((state.event == PM_EVENT_SUSPEND)
}
+/*
+ * This is called with interrupts off, only a single CPU
+ * running. We can't do down() on a semaphore (and we don't
+ * need the protection)
+ */
+static int suspend_device_late(struct device *dev, pm_message_t state)
+{
+ int error = 0;
+
+ if (dev->bus && dev->bus->suspend_late && !dev->power.power_state.event) {
+ dev_dbg(dev, "LATE %s%s\n",
+ suspend_verb(state.event),
+ ((state.event == PM_EVENT_SUSPEND)
+ && device_may_wakeup(dev))
+ ? ", may wakeup"
+ : ""
+ );
+ error = dev->bus->suspend_late(dev, state);
+ suspend_report_result(dev->bus->suspend_late, error);
+ }
+ return error;
+}
+
/**
* device_suspend - Save state and stop all devices in system.
* @state: Power state to put each device in.
*
* Walk the dpm_active list, call ->suspend() for each device, and move
- * it to dpm_off.
- * Check the return value for each. If it returns 0, then we move the
- * the device to the dpm_off list. If it returns -EAGAIN, we move it to
- * the dpm_off_irq list. If we get a different error, try and back out.
+ * it to the dpm_off list.
+ *
+ * (For historical reasons, if it returns -EAGAIN, that used to mean
+ * that the device would be called again with interrupts disabled.
+ * These days, we use the "suspend_late()" callback for that, so we
+ * print a warning and consider it an error).
+ *
+ * If we get a different error, try and back out.
*
* If we hit a failure with any of the devices, call device_resume()
* above to bring the suspended devices back to life.
{
int error = 0;
+ might_sleep();
down(&dpm_sem);
down(&dpm_list_sem);
while (!list_empty(&dpm_active) && error == 0) {
/* Check if the device got removed */
if (!list_empty(&dev->power.entry)) {
- /* Move it to the dpm_off or dpm_off_irq list */
+ /* Move it to the dpm_off list */
if (!error)
list_move(&dev->power.entry, &dpm_off);
- else if (error == -EAGAIN) {
- list_move(&dev->power.entry, &dpm_off_irq);
- error = 0;
- }
}
if (error)
printk(KERN_ERR "Could not suspend device %s: "
- "error %d\n", kobject_name(&dev->kobj), error);
+ "error %d%s\n",
+ kobject_name(&dev->kobj), error,
+ error == -EAGAIN ? " (please convert to suspend_late)" : "");
put_device(dev);
}
up(&dpm_list_sem);
- if (error) {
- /* we failed... before resuming, bring back devices from
- * dpm_off_irq list back to main dpm_off list, we do want
- * to call resume() on them, in case they partially suspended
- * despite returning -EAGAIN
- */
- while (!list_empty(&dpm_off_irq)) {
- struct list_head * entry = dpm_off_irq.next;
- list_move(entry, &dpm_off);
- }
+ if (error)
dpm_resume();
- }
+
up(&dpm_sem);
return error;
}
EXPORT_SYMBOL_GPL(device_suspend);
-
/**
* device_power_down - Shut down special devices.
* @state: Power state to enter.
int error = 0;
struct device * dev;
- list_for_each_entry_reverse(dev, &dpm_off_irq, power.entry) {
- if ((error = suspend_device(dev, state)))
- break;
+ while (!list_empty(&dpm_off)) {
+ struct list_head * entry = dpm_off.prev;
+
+ dev = to_device(entry);
+ error = suspend_device_late(dev, state);
+ if (error)
+ goto Error;
+ list_move(&dev->power.entry, &dpm_off_irq);
}
- if (error)
- goto Error;
- if ((error = sysdev_suspend(state)))
- goto Error;
+
+ error = sysdev_suspend(state);
Done:
return error;
Error:
#include "power.h"
+#ifdef CONFIG_PM_SYSFS_DEPRECATED
+
/**
* state - Control current power state of device
*
* show() returns the current power state of the device. '0' indicates
- * the device is on. Other values (1-3) indicate the device is in a low
+ * the device is on. Other values (2) indicate the device is in some low
* power state.
*
- * store() sets the current power state, which is an integer value
- * between 0-3. If the device is on ('0'), and the value written is
- * greater than 0, then the device is placed directly into the low-power
- * state (via its driver's ->suspend() method).
- * If the device is currently in a low-power state, and the value is 0,
- * the device is powered back on (via the ->resume() method).
- * If the device is in a low-power state, and a different low-power state
- * is requested, the device is first resumed, then suspended into the new
- * low-power state.
+ * store() sets the current power state, which is an integer valued
+ * 0, 2, or 3. Devices with bus.suspend_late(), or bus.resume_early()
+ * methods fail this operation; those methods couldn't be called.
+ * Otherwise,
+ *
+ * - If the recorded dev->power.power_state.event matches the
+ * target value, nothing is done.
+ * - If the recorded event code is nonzero, the device is reactivated
+ * by calling bus.resume() and/or class.resume().
+ * - If the target value is nonzero, the device is suspended by
+ * calling class.suspend() and/or bus.suspend() with event code
+ * PM_EVENT_SUSPEND.
+ *
+ * This mechanism is DEPRECATED and should only be used for testing.
*/
static ssize_t state_show(struct device * dev, struct device_attribute *attr, char * buf)
pm_message_t state;
int error = -EINVAL;
+ /* disallow incomplete suspend sequences */
+ if (dev->bus && (dev->bus->suspend_late || dev->bus->resume_early))
+ return error;
+
state.event = PM_EVENT_SUSPEND;
/* Older apps expected to write "3" here - confused with PCI D3 */
if ((n == 1) && !strcmp(buf, "3"))
static DEVICE_ATTR(state, 0644, state_show, state_store);
+#endif /* CONFIG_PM_SYSFS_DEPRECATED */
+
/*
* wakeup - Report/change current wakeup option for device
*
static struct attribute * power_attrs[] = {
+#ifdef CONFIG_PM_SYSFS_DEPRECATED
&dev_attr_state.attr,
+#endif
&dev_attr_wakeup.attr,
NULL,
};
EXPORT_SYMBOL(system_bus_clock);
-static int generic_ide_suspend(struct device *dev, pm_message_t state)
+static int generic_ide_suspend(struct device *dev, pm_message_t mesg)
{
ide_drive_t *drive = dev->driver_data;
struct request rq;
rq.special = &args;
rq.end_io_data = &rqpm;
rqpm.pm_step = ide_pm_state_start_suspend;
- rqpm.pm_state = state.event;
+ if (mesg.event == PM_EVENT_PRETHAW)
+ mesg.event = PM_EVENT_FREEZE;
+ rqpm.pm_state = mesg.event;
return ide_do_drive_cmd(drive, &rq, ide_wait);
}
}
static int
-pmac_ide_macio_suspend(struct macio_dev *mdev, pm_message_t state)
+pmac_ide_macio_suspend(struct macio_dev *mdev, pm_message_t mesg)
{
ide_hwif_t *hwif = (ide_hwif_t *)dev_get_drvdata(&mdev->ofdev.dev);
int rc = 0;
- if (state.event != mdev->ofdev.dev.power.power_state.event && state.event >= PM_EVENT_SUSPEND) {
+ if (mesg.event != mdev->ofdev.dev.power.power_state.event
+ && mesg.event == PM_EVENT_SUSPEND) {
rc = pmac_ide_do_suspend(hwif);
if (rc == 0)
- mdev->ofdev.dev.power.power_state = state;
+ mdev->ofdev.dev.power.power_state = mesg;
}
return rc;
}
static int
-pmac_ide_pci_suspend(struct pci_dev *pdev, pm_message_t state)
+pmac_ide_pci_suspend(struct pci_dev *pdev, pm_message_t mesg)
{
ide_hwif_t *hwif = (ide_hwif_t *)pci_get_drvdata(pdev);
int rc = 0;
- if (state.event != pdev->dev.power.power_state.event && state.event >= 2) {
+ if (mesg.event != pdev->dev.power.power_state.event
+ && mesg.event == PM_EVENT_SUSPEND) {
rc = pmac_ide_do_suspend(hwif);
if (rc == 0)
- pdev->dev.power.power_state = state;
+ pdev->dev.power.power_state = mesg;
}
return rc;
if (cinergyt2->disconnect_pending || mutex_lock_interruptible(&cinergyt2->sem))
return -ERESTARTSYS;
- if (state.event > PM_EVENT_ON) {
+ if (1) {
struct cinergyt2 *cinergyt2 = usb_get_intfdata (intf);
cinergyt2_suspend_rc(cinergyt2);
If you don't know what to do here, say N.
+config PCI_MULTITHREAD_PROBE
+ bool "PCI Multi-threaded probe (EXPERIMENTAL)"
+ depends on PCI && EXPERIMENTAL
+ help
+ Say Y here if you want the PCI core to spawn a new thread for
+ every PCI device that is probed. This can cause a huge
+ speedup in boot times on multiprocessor machines, and even a
+ smaller speedup on single processor machines.
+
+ But it can also cause lots of bad things to happen. A number
+ of PCI drivers can not properly handle running in this way,
+ some will just not work properly at all, while others might
+ decide to blow up power supplies with a huge load all at once,
+ so use this option at your own risk.
+
+ It is very unwise to use this option if you are not using a
+ boot process that can handle devices being created in any
+ order. A program that can create persistant block and network
+ device names (like udev) is a good idea if you wish to use
+ this option.
+
+ Again, use this option at your own risk, you have been warned!
+
+ When in doubt, say N.
+
config PCI_DEBUG
bool "PCI Debugging"
depends on PCI && DEBUG_KERNEL
if (ACPI_FAILURE(status))
err("%s: Notification handler removal failed\n", __FUNCTION__);
/* remove the /sys entries */
- if (sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr))
- err("%s: removal of sysfs file apci_table failed\n",
- __FUNCTION__);
+ sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr);
}
module_init(ibm_acpiphp_init);
* Registration of PCI drivers and handling of hot-pluggable devices.
*/
+/* multithreaded probe logic */
+static int pci_multithread_probe =
+#ifdef CONFIG_PCI_MULTITHREAD_PROBE
+ 1;
+#else
+ 0;
+#endif
+__module_param_call("", pci_multithread_probe, param_set_bool, param_get_bool, &pci_multithread_probe, 0644);
+
+
/*
* Dynamic device IDs are disabled for !CONFIG_HOTPLUG
*/
return i;
}
+static int pci_device_suspend_late(struct device * dev, pm_message_t state)
+{
+ struct pci_dev * pci_dev = to_pci_dev(dev);
+ struct pci_driver * drv = pci_dev->driver;
+ int i = 0;
+
+ if (drv && drv->suspend_late) {
+ i = drv->suspend_late(pci_dev, state);
+ suspend_report_result(drv->suspend_late, i);
+ }
+ return i;
+}
/*
* Default resume method for devices that have no driver provided resume,
return error;
}
+static int pci_device_resume_early(struct device * dev)
+{
+ int error = 0;
+ struct pci_dev * pci_dev = to_pci_dev(dev);
+ struct pci_driver * drv = pci_dev->driver;
+
+ if (drv && drv->resume_early)
+ error = drv->resume_early(pci_dev);
+ return error;
+}
+
static void pci_device_shutdown(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
drv->driver.bus = &pci_bus_type;
drv->driver.owner = owner;
drv->driver.kobj.ktype = &pci_driver_kobj_type;
+ drv->driver.multithread_probe = pci_multithread_probe;
spin_lock_init(&drv->dynids.lock);
INIT_LIST_HEAD(&drv->dynids.list);
.probe = pci_device_probe,
.remove = pci_device_remove,
.suspend = pci_device_suspend,
- .shutdown = pci_device_shutdown,
+ .suspend_late = pci_device_suspend_late,
+ .resume_early = pci_device_resume_early,
.resume = pci_device_resume,
+ .shutdown = pci_device_shutdown,
.dev_attrs = pci_dev_attrs,
};
case PM_EVENT_ON:
return PCI_D0;
case PM_EVENT_FREEZE:
+ case PM_EVENT_PRETHAW:
+ /* REVISIT both freeze and pre-thaw "should" use D0 */
case PM_EVENT_SUSPEND:
return PCI_D3hot;
default:
- printk("They asked me for state %d\n", state.event);
+ printk("Unrecognized suspend event %d\n", state.event);
BUG();
}
return PCI_D0;
pmac_call_feature(PMAC_FTR_MESH_ENABLE, macio_get_of_node(ms->mdev), 0, 0);
msleep(10);
}
-}
+}
#ifdef CONFIG_PM
-static int mesh_suspend(struct macio_dev *mdev, pm_message_t state)
+static int mesh_suspend(struct macio_dev *mdev, pm_message_t mesg)
{
struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
unsigned long flags;
- if (state.event == mdev->ofdev.dev.power.power_state.event || state.event < 2)
+ switch (mesg.event) {
+ case PM_EVENT_SUSPEND:
+ case PM_EVENT_FREEZE:
+ break;
+ default:
+ return 0;
+ }
+ if (mesg.event == mdev->ofdev.dev.power.power_state.event)
return 0;
scsi_block_requests(ms->host);
disable_irq(ms->meshintr);
set_mesh_power(ms, 0);
- mdev->ofdev.dev.power.power_state = state;
+ mdev->ofdev.dev.power.power_state = mesg;
return 0;
}
(void) usb_hcd_pci_resume (dev);
}
- } else {
+ } else if (hcd->state != HC_STATE_HALT) {
dev_dbg (hcd->self.controller, "hcd state %d; not suspended\n",
hcd->state);
WARN_ON(1);
writel (0, &ehci->regs->intr_enable);
(void)readl(&ehci->regs->intr_enable);
+ /* make sure snapshot being resumed re-enumerates everything */
+ if (message.event == PM_EVENT_PRETHAW) {
+ ehci_halt(ehci);
+ ehci_reset(ehci);
+ }
+
clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
bail:
spin_unlock_irqrestore (&ehci->lock, flags);
}
ohci_writel(ohci, OHCI_INTR_MIE, &ohci->regs->intrdisable);
(void)ohci_readl(ohci, &ohci->regs->intrdisable);
+
+ /* make sure snapshot being resumed re-enumerates everything */
+ if (message.event == PM_EVENT_PRETHAW)
+ ohci_usb_reset(ohci);
+
clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
bail:
spin_unlock_irqrestore (&ohci->lock, flags);
struct sl811 *sl811 = hcd_to_sl811(hcd);
int retval = 0;
- if (state.event == PM_EVENT_FREEZE)
+ switch (state.event) {
+ case PM_EVENT_FREEZE:
retval = sl811h_bus_suspend(hcd);
- else if (state.event == PM_EVENT_SUSPEND)
+ break;
+ case PM_EVENT_SUSPEND:
+ case PM_EVENT_PRETHAW: /* explicitly discard hw state */
port_power(sl811, 0);
+ break;
+ }
if (retval == 0)
dev->dev.power.power_state = state;
return retval;
/* FIXME: Enable non-PME# remote wakeup? */
+ /* make sure snapshot being resumed re-enumerates everything */
+ if (message.event == PM_EVENT_PRETHAW)
+ uhci_hc_died(uhci);
+
done_okay:
clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
done:
}
-int radeonfb_pci_suspend(struct pci_dev *pdev, pm_message_t state)
+int radeonfb_pci_suspend(struct pci_dev *pdev, pm_message_t mesg)
{
struct fb_info *info = pci_get_drvdata(pdev);
struct radeonfb_info *rinfo = info->par;
int i;
- if (state.event == pdev->dev.power.power_state.event)
+ if (mesg.event == pdev->dev.power.power_state.event)
return 0;
- printk(KERN_DEBUG "radeonfb (%s): suspending to state: %d...\n",
- pci_name(pdev), state.event);
+ printk(KERN_DEBUG "radeonfb (%s): suspending for event: %d...\n",
+ pci_name(pdev), mesg.event);
/* For suspend-to-disk, we cheat here. We don't suspend anything and
* let fbcon continue drawing until we are all set. That shouldn't
* really cause any problem at this point, provided that the wakeup
* code knows that any state in memory may not match the HW
*/
- if (state.event == PM_EVENT_FREEZE)
+ switch (mesg.event) {
+ case PM_EVENT_FREEZE: /* about to take snapshot */
+ case PM_EVENT_PRETHAW: /* before restoring snapshot */
goto done;
+ }
acquire_console_sem();
release_console_sem();
done:
- pdev->dev.power.power_state = state;
+ pdev->dev.power.power_state = mesg;
return 0;
}
/***********************************************************************
* Power Management *
***********************************************************************/
-static int i810fb_suspend(struct pci_dev *dev, pm_message_t state)
+static int i810fb_suspend(struct pci_dev *dev, pm_message_t mesg)
{
struct fb_info *info = pci_get_drvdata(dev);
struct i810fb_par *par = info->par;
- par->cur_state = state.event;
+ par->cur_state = mesg.event;
- if (state.event == PM_EVENT_FREEZE) {
- dev->dev.power.power_state = state;
+ switch (mesg.event) {
+ case PM_EVENT_FREEZE:
+ case PM_EVENT_PRETHAW:
+ dev->dev.power.power_state = mesg;
return 0;
}
pci_save_state(dev);
pci_disable_device(dev);
- pci_set_power_state(dev, pci_choose_state(dev, state));
+ pci_set_power_state(dev, pci_choose_state(dev, mesg));
release_console_sem();
return 0;
};
#ifdef CONFIG_PM
-static int nvidiafb_suspend(struct pci_dev *dev, pm_message_t state)
+static int nvidiafb_suspend(struct pci_dev *dev, pm_message_t mesg)
{
struct fb_info *info = pci_get_drvdata(dev);
struct nvidia_par *par = info->par;
+ if (mesg.event == PM_EVENT_PRETHAW)
+ mesg.event = PM_EVENT_FREEZE;
acquire_console_sem();
- par->pm_state = state.event;
+ par->pm_state = mesg.event;
- if (state.event == PM_EVENT_FREEZE) {
- dev->dev.power.power_state = state;
- } else {
+ if (mesg.event == PM_EVENT_SUSPEND) {
fb_set_suspend(info, 1);
nvidiafb_blank(FB_BLANK_POWERDOWN, info);
nvidia_write_regs(par, &par->SavedReg);
pci_save_state(dev);
pci_disable_device(dev);
- pci_set_power_state(dev, pci_choose_state(dev, state));
+ pci_set_power_state(dev, pci_choose_state(dev, mesg));
}
+ dev->dev.power.power_state = mesg;
release_console_sem();
return 0;
}
}
-static int savagefb_suspend(struct pci_dev* dev, pm_message_t state)
+static int savagefb_suspend(struct pci_dev *dev, pm_message_t mesg)
{
struct fb_info *info = pci_get_drvdata(dev);
struct savagefb_par *par = info->par;
DBG("savagefb_suspend");
-
- par->pm_state = state.event;
+ if (mesg.event == PM_EVENT_PRETHAW)
+ mesg.event = PM_EVENT_FREEZE;
+ par->pm_state = mesg.event;
+ dev->dev.power.power_state = mesg;
/*
* For PM_EVENT_FREEZE, do not power down so the console
* can remain active.
*/
- if (state.event == PM_EVENT_FREEZE) {
- dev->dev.power.power_state = state;
+ if (mesg.event == PM_EVENT_FREEZE)
return 0;
- }
acquire_console_sem();
fb_set_suspend(info, 1);
savage_disable_mmio(par);
pci_save_state(dev);
pci_disable_device(dev);
- pci_set_power_state(dev, pci_choose_state(dev, state));
+ pci_set_power_state(dev, pci_choose_state(dev, mesg));
release_console_sem();
return 0;
DEFINE_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");
/**
- * debugfs_create_u8 - create a file in the debugfs filesystem that is used to read and write an unsigned 8 bit value.
- *
+ * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value
* @name: a pointer to a string containing the name of the file to create.
* @mode: the permission that the file should have
* @parent: a pointer to the parent dentry for this file. This should be a
- * directory dentry if set. If this paramater is NULL, then the
+ * directory dentry if set. If this parameter is %NULL, then the
* file will be created in the root of the debugfs filesystem.
* @value: a pointer to the variable that the file should read to and write
* from.
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.) If an error occurs, NULL will be returned.
+ * you are responsible here.) If an error occurs, %NULL will be returned.
*
- * If debugfs is not enabled in the kernel, the value -ENODEV will be
+ * If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
- * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
+ * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *debugfs_create_u8(const char *name, mode_t mode,
DEFINE_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");
/**
- * debugfs_create_u16 - create a file in the debugfs filesystem that is used to read and write an unsigned 16 bit value.
- *
+ * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value
* @name: a pointer to a string containing the name of the file to create.
* @mode: the permission that the file should have
* @parent: a pointer to the parent dentry for this file. This should be a
- * directory dentry if set. If this paramater is NULL, then the
+ * directory dentry if set. If this parameter is %NULL, then the
* file will be created in the root of the debugfs filesystem.
* @value: a pointer to the variable that the file should read to and write
* from.
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.) If an error occurs, NULL will be returned.
+ * you are responsible here.) If an error occurs, %NULL will be returned.
*
- * If debugfs is not enabled in the kernel, the value -ENODEV will be
+ * If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
- * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
+ * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *debugfs_create_u16(const char *name, mode_t mode,
DEFINE_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");
/**
- * debugfs_create_u32 - create a file in the debugfs filesystem that is used to read and write an unsigned 32 bit value.
- *
+ * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value
* @name: a pointer to a string containing the name of the file to create.
* @mode: the permission that the file should have
* @parent: a pointer to the parent dentry for this file. This should be a
- * directory dentry if set. If this paramater is NULL, then the
+ * directory dentry if set. If this parameter is %NULL, then the
* file will be created in the root of the debugfs filesystem.
* @value: a pointer to the variable that the file should read to and write
* from.
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.) If an error occurs, NULL will be returned.
+ * you are responsible here.) If an error occurs, %NULL will be returned.
*
- * If debugfs is not enabled in the kernel, the value -ENODEV will be
+ * If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
- * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
+ * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *debugfs_create_u32(const char *name, mode_t mode,
};
/**
- * debugfs_create_bool - create a file in the debugfs filesystem that is used to read and write a boolean value.
- *
+ * debugfs_create_bool - create a debugfs file that is used to read and write a boolean value
* @name: a pointer to a string containing the name of the file to create.
* @mode: the permission that the file should have
* @parent: a pointer to the parent dentry for this file. This should be a
- * directory dentry if set. If this paramater is NULL, then the
+ * directory dentry if set. If this parameter is %NULL, then the
* file will be created in the root of the debugfs filesystem.
* @value: a pointer to the variable that the file should read to and write
* from.
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.) If an error occurs, NULL will be returned.
+ * you are responsible here.) If an error occurs, %NULL will be returned.
*
- * If debugfs is not enabled in the kernel, the value -ENODEV will be
+ * If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
- * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
+ * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *debugfs_create_bool(const char *name, mode_t mode,
};
/**
- * debugfs_create_blob - create a file in the debugfs filesystem that is
- * used to read and write a binary blob.
- *
+ * debugfs_create_blob - create a debugfs file that is used to read and write a binary blob
* @name: a pointer to a string containing the name of the file to create.
* @mode: the permission that the file should have
* @parent: a pointer to the parent dentry for this file. This should be a
- * directory dentry if set. If this paramater is NULL, then the
+ * directory dentry if set. If this parameter is %NULL, then the
* file will be created in the root of the debugfs filesystem.
* @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer
* to the blob data and the size of the data.
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.) If an error occurs, NULL will be returned.
+ * you are responsible here.) If an error occurs, %NULL will be returned.
*
- * If debugfs is not enabled in the kernel, the value -ENODEV will be
+ * If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
- * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
+ * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *debugfs_create_blob(const char *name, mode_t mode,
/**
* debugfs_create_file - create a file in the debugfs filesystem
- *
* @name: a pointer to a string containing the name of the file to create.
* @mode: the permission that the file should have
* @parent: a pointer to the parent dentry for this file. This should be a
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.) If an error occurs, NULL will be returned.
+ * you are responsible here.) If an error occurs, %NULL will be returned.
*
- * If debugfs is not enabled in the kernel, the value -ENODEV will be
+ * If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
- * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
+ * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *debugfs_create_file(const char *name, mode_t mode,
/**
* debugfs_create_dir - create a directory in the debugfs filesystem
- *
* @name: a pointer to a string containing the name of the directory to
* create.
* @parent: a pointer to the parent dentry for this file. This should be a
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.) If an error occurs, NULL will be returned.
+ * you are responsible here.) If an error occurs, %NULL will be returned.
*
- * If debugfs is not enabled in the kernel, the value -ENODEV will be
+ * If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
- * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
+ * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *debugfs_create_dir(const char *name, struct dentry *parent)
/**
* debugfs_remove - removes a file or directory from the debugfs filesystem
- *
* @dentry: a pointer to a the dentry of the file or directory to be
* removed.
*
#include <linux/acct.h>
#include <linux/capability.h>
#include <linux/module.h>
+#include <linux/sysfs.h>
#include <linux/seq_file.h>
#include <linux/namespace.h>
#include <linux/namei.h>
extern int __init init_rootfs(void);
-#ifdef CONFIG_SYSFS
-extern int __init sysfs_init(void);
-#else
-static inline int sysfs_init(void)
-{
- return 0;
-}
-#endif
-
/* spinlock for vfsmount related operations, inplace of dcache_lock */
__cacheline_aligned_in_smp DEFINE_SPINLOCK(vfsmount_lock);
#include <linux/errno.h>
#include <linux/fs.h>
+#include <linux/kernel.h>
#include <linux/kobject.h>
#include <linux/module.h>
#include <linux/slab.h>
* sysfs_create_bin_file - create binary file for object.
* @kobj: object.
* @attr: attribute descriptor.
- *
*/
int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr)
* sysfs_remove_bin_file - remove binary file for object.
* @kobj: object.
* @attr: attribute descriptor.
- *
*/
-int sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr)
+void sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr)
{
- sysfs_hash_and_remove(kobj->dentry,attr->attr.name);
- return 0;
+ if (sysfs_hash_and_remove(kobj->dentry, attr->attr.name) < 0) {
+ printk(KERN_ERR "%s: "
+ "bad dentry or inode or no such file: \"%s\"\n",
+ __FUNCTION__, attr->attr.name);
+ dump_stack();
+ }
}
EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
memset(sd, 0, sizeof(*sd));
atomic_set(&sd->s_count, 1);
- atomic_set(&sd->s_event, 0);
+ atomic_set(&sd->s_event, 1);
INIT_LIST_HEAD(&sd->s_children);
list_add(&sd->s_sibling, &parent_sd->s_children);
sd->s_element = element;
#include <linux/namei.h>
#include <linux/backing-dev.h>
#include <linux/capability.h>
+#include <linux/errno.h>
#include "sysfs.h"
extern struct super_block * sysfs_sb;
}
}
-void sysfs_hash_and_remove(struct dentry * dir, const char * name)
+int sysfs_hash_and_remove(struct dentry * dir, const char * name)
{
struct sysfs_dirent * sd;
struct sysfs_dirent * parent_sd;
+ int found = 0;
if (!dir)
- return;
+ return -ENOENT;
if (dir->d_inode == NULL)
/* no inode means this hasn't been made visible yet */
- return;
+ return -ENOENT;
parent_sd = dir->d_fsdata;
mutex_lock(&dir->d_inode->i_mutex);
list_del_init(&sd->s_sibling);
sysfs_drop_dentry(sd, dir);
sysfs_put(sd);
+ found = 1;
break;
}
}
mutex_unlock(&dir->d_inode->i_mutex);
+
+ return found ? 0 : -ENOENT;
}
*/
#include <linux/fs.h>
+#include <linux/mount.h>
#include <linux/module.h>
#include <linux/kobject.h>
#include <linux/namei.h>
*/
int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char * name)
{
- struct dentry * dentry = kobj->dentry;
+ struct dentry *dentry = NULL;
int error = -EEXIST;
- BUG_ON(!kobj || !kobj->dentry || !name);
+ BUG_ON(!name);
+
+ if (!kobj) {
+ if (sysfs_mount && sysfs_mount->mnt_sb)
+ dentry = sysfs_mount->mnt_sb->s_root;
+ } else
+ dentry = kobj->dentry;
+
+ if (!dentry)
+ return -EFAULT;
mutex_lock(&dentry->d_inode->i_mutex);
if (!sysfs_dirent_exist(dentry->d_fsdata, name))
umode_t, int);
extern int sysfs_add_file(struct dentry *, const struct attribute *, int);
-extern void sysfs_hash_and_remove(struct dentry * dir, const char * name);
+extern int sysfs_hash_and_remove(struct dentry * dir, const char * name);
extern struct sysfs_dirent *sysfs_find(struct sysfs_dirent *dir, const char * name);
extern int sysfs_create_subdir(struct kobject *, const char *, struct dentry **);
#define __must_check
#endif
+#ifndef CONFIG_ENABLE_MUST_CHECK
+#undef __must_check
+#define __must_check
+#endif
+
/*
* Allow us to avoid 'defined but not used' warnings on functions and data,
* as well as force them to be emitted to the assembly file.
#include <linux/kobject.h>
#include <linux/klist.h>
#include <linux/list.h>
+#include <linux/compiler.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/pm.h>
int (*probe)(struct device * dev);
int (*remove)(struct device * dev);
void (*shutdown)(struct device * dev);
- int (*suspend)(struct device * dev, pm_message_t state);
- int (*resume)(struct device * dev);
+
+ int (*suspend)(struct device * dev, pm_message_t state);
+ int (*suspend_late)(struct device * dev, pm_message_t state);
+ int (*resume_early)(struct device * dev);
+ int (*resume)(struct device * dev);
};
-extern int bus_register(struct bus_type * bus);
+extern int __must_check bus_register(struct bus_type * bus);
extern void bus_unregister(struct bus_type * bus);
-extern void bus_rescan_devices(struct bus_type * bus);
+extern int __must_check bus_rescan_devices(struct bus_type * bus);
/* iterator helpers for buses */
struct device * bus_find_device(struct bus_type *bus, struct device *start,
void *data, int (*match)(struct device *, void *));
-int bus_for_each_drv(struct bus_type * bus, struct device_driver * start,
- void * data, int (*fn)(struct device_driver *, void *));
-
+int __must_check bus_for_each_drv(struct bus_type *bus,
+ struct device_driver *start, void *data,
+ int (*fn)(struct device_driver *, void *));
/* driverfs interface for exporting bus attributes */
#define BUS_ATTR(_name,_mode,_show,_store) \
struct bus_attribute bus_attr_##_name = __ATTR(_name,_mode,_show,_store)
-extern int bus_create_file(struct bus_type *, struct bus_attribute *);
+extern int __must_check bus_create_file(struct bus_type *,
+ struct bus_attribute *);
extern void bus_remove_file(struct bus_type *, struct bus_attribute *);
struct device_driver {
void (*shutdown) (struct device * dev);
int (*suspend) (struct device * dev, pm_message_t state);
int (*resume) (struct device * dev);
+
+ unsigned int multithread_probe:1;
};
-extern int driver_register(struct device_driver * drv);
+extern int __must_check driver_register(struct device_driver * drv);
extern void driver_unregister(struct device_driver * drv);
extern struct device_driver * get_driver(struct device_driver * drv);
extern void put_driver(struct device_driver * drv);
extern struct device_driver *driver_find(const char *name, struct bus_type *bus);
-
+extern int driver_probe_done(void);
/* driverfs interface for exporting driver attributes */
#define DRIVER_ATTR(_name,_mode,_show,_store) \
struct driver_attribute driver_attr_##_name = __ATTR(_name,_mode,_show,_store)
-extern int driver_create_file(struct device_driver *, struct driver_attribute *);
+extern int __must_check driver_create_file(struct device_driver *,
+ struct driver_attribute *);
extern void driver_remove_file(struct device_driver *, struct driver_attribute *);
-extern int driver_for_each_device(struct device_driver * drv, struct device * start,
- void * data, int (*fn)(struct device *, void *));
+extern int __must_check driver_for_each_device(struct device_driver * drv,
+ struct device *start, void *data,
+ int (*fn)(struct device *, void *));
struct device * driver_find_device(struct device_driver *drv,
struct device *start, void *data,
int (*match)(struct device *, void *));
-
/*
* device classes
*/
struct list_head interfaces;
struct semaphore sem; /* locks both the children and interfaces lists */
+ struct kobject *virtual_dir;
+
struct class_attribute * class_attrs;
struct class_device_attribute * class_dev_attrs;
+ struct device_attribute * dev_attrs;
int (*uevent)(struct class_device *dev, char **envp,
int num_envp, char *buffer, int buffer_size);
+ int (*dev_uevent)(struct device *dev, char **envp, int num_envp,
+ char *buffer, int buffer_size);
void (*release)(struct class_device *dev);
void (*class_release)(struct class *class);
+ void (*dev_release)(struct device *dev);
+
+ int (*suspend)(struct device *, pm_message_t state);
+ int (*resume)(struct device *);
};
-extern int class_register(struct class *);
+extern int __must_check class_register(struct class *);
extern void class_unregister(struct class *);
#define CLASS_ATTR(_name,_mode,_show,_store) \
struct class_attribute class_attr_##_name = __ATTR(_name,_mode,_show,_store)
-extern int class_create_file(struct class *, const struct class_attribute *);
+extern int __must_check class_create_file(struct class *,
+ const struct class_attribute *);
extern void class_remove_file(struct class *, const struct class_attribute *);
struct class_device_attribute {
struct class_device_attribute class_device_attr_##_name = \
__ATTR(_name,_mode,_show,_store)
-extern int class_device_create_file(struct class_device *,
+extern int __must_check class_device_create_file(struct class_device *,
const struct class_device_attribute *);
/**
}
-extern int class_device_register(struct class_device *);
+extern int __must_check class_device_register(struct class_device *);
extern void class_device_unregister(struct class_device *);
extern void class_device_initialize(struct class_device *);
-extern int class_device_add(struct class_device *);
+extern int __must_check class_device_add(struct class_device *);
extern void class_device_del(struct class_device *);
extern int class_device_rename(struct class_device *, char *);
extern void class_device_remove_file(struct class_device *,
const struct class_device_attribute *);
-extern int class_device_create_bin_file(struct class_device *,
+extern int __must_check class_device_create_bin_file(struct class_device *,
struct bin_attribute *);
extern void class_device_remove_bin_file(struct class_device *,
struct bin_attribute *);
int (*add) (struct class_device *, struct class_interface *);
void (*remove) (struct class_device *, struct class_interface *);
+ int (*add_dev) (struct device *, struct class_interface *);
+ void (*remove_dev) (struct device *, struct class_interface *);
};
-extern int class_interface_register(struct class_interface *);
+extern int __must_check class_interface_register(struct class_interface *);
extern void class_interface_unregister(struct class_interface *);
-extern struct class *class_create(struct module *owner, char *name);
+extern struct class *class_create(struct module *owner, const char *name);
extern void class_destroy(struct class *cls);
extern struct class_device *class_device_create(struct class *cls,
struct class_device *parent,
dev_t devt,
struct device *device,
- char *fmt, ...)
+ const char *fmt, ...)
__attribute__((format(printf,5,6)));
extern void class_device_destroy(struct class *cls, dev_t devt);
-
/* interface for exporting device attributes */
struct device_attribute {
struct attribute attr;
#define DEVICE_ATTR(_name,_mode,_show,_store) \
struct device_attribute dev_attr_##_name = __ATTR(_name,_mode,_show,_store)
-extern int device_create_file(struct device *device, struct device_attribute * entry);
+extern int __must_check device_create_file(struct device *device,
+ struct device_attribute * entry);
extern void device_remove_file(struct device * dev, struct device_attribute * attr);
+extern int __must_check device_create_bin_file(struct device *dev,
+ struct bin_attribute *attr);
+extern void device_remove_bin_file(struct device *dev,
+ struct bin_attribute *attr);
struct device {
struct klist klist_children;
struct klist_node knode_parent; /* node in sibling list */
struct kobject kobj;
char bus_id[BUS_ID_SIZE]; /* position on parent bus */
+ unsigned is_registered:1;
struct device_attribute uevent_attr;
struct device_attribute *devt_attr;
struct list_head node;
struct class *class; /* optional*/
dev_t devt; /* dev_t, creates the sysfs "dev" */
+ struct attribute_group **groups; /* optional groups */
void (*release)(struct device * dev);
};
static inline int device_is_registered(struct device *dev)
{
- return klist_node_attached(&dev->knode_bus);
+ return dev->is_registered;
}
/*
* High level routines for use by the bus drivers
*/
-extern int device_register(struct device * dev);
+extern int __must_check device_register(struct device * dev);
extern void device_unregister(struct device * dev);
extern void device_initialize(struct device * dev);
-extern int device_add(struct device * dev);
+extern int __must_check device_add(struct device * dev);
extern void device_del(struct device * dev);
-extern int device_for_each_child(struct device *, void *,
+extern int __must_check device_for_each_child(struct device *, void *,
int (*fn)(struct device *, void *));
+extern int device_rename(struct device *dev, char *new_name);
/*
* Manual binding of a device to driver. See drivers/base/bus.c
* for information on use.
*/
-extern void device_bind_driver(struct device * dev);
+extern int __must_check device_bind_driver(struct device *dev);
extern void device_release_driver(struct device * dev);
-extern int device_attach(struct device * dev);
-extern void driver_attach(struct device_driver * drv);
-extern void device_reprobe(struct device *dev);
+extern int __must_check device_attach(struct device * dev);
+extern int __must_check driver_attach(struct device_driver *drv);
+extern int __must_check device_reprobe(struct device *dev);
/*
* Easy functions for dynamically creating devices on the fly
*/
extern struct device *device_create(struct class *cls, struct device *parent,
- dev_t devt, char *fmt, ...)
+ dev_t devt, const char *fmt, ...)
__attribute__((format(printf,4,5)));
extern void device_destroy(struct class *cls, dev_t devt);
+extern int virtual_device_parent(struct device *dev);
+
/*
* Platform "fixup" functions - allow the platform to have their say
* about devices and actions that the general device layer doesn't
/* drivers/base/firmware.c */
-extern int firmware_register(struct subsystem *);
+extern int __must_check firmware_register(struct subsystem *);
extern void firmware_unregister(struct subsystem *);
/* debugging and troubleshooting/diagnostic helpers. */
#include <linux/types.h>
#include <linux/list.h>
#include <linux/sysfs.h>
+#include <linux/compiler.h>
#include <linux/spinlock.h>
#include <linux/rwsem.h>
#include <linux/kref.h>
extern void kobject_init(struct kobject *);
extern void kobject_cleanup(struct kobject *);
-extern int kobject_add(struct kobject *);
+extern int __must_check kobject_add(struct kobject *);
extern void kobject_del(struct kobject *);
-extern int kobject_rename(struct kobject *, const char *new_name);
+extern int __must_check kobject_rename(struct kobject *, const char *new_name);
-extern int kobject_register(struct kobject *);
+extern int __must_check kobject_register(struct kobject *);
extern void kobject_unregister(struct kobject *);
extern struct kobject * kobject_get(struct kobject *);
extern void kset_init(struct kset * k);
-extern int kset_add(struct kset * k);
-extern int kset_register(struct kset * k);
+extern int __must_check kset_add(struct kset * k);
+extern int __must_check kset_register(struct kset * k);
extern void kset_unregister(struct kset * k);
static inline struct kset * to_kset(struct kobject * kobj)
(obj)->subsys.kset.kobj.kset = &(_subsys).kset
extern void subsystem_init(struct subsystem *);
-extern int subsystem_register(struct subsystem *);
+extern int __must_check subsystem_register(struct subsystem *);
extern void subsystem_unregister(struct subsystem *);
static inline struct subsystem * subsys_get(struct subsystem * s)
ssize_t (*store)(struct subsystem *, const char *, size_t);
};
-extern int subsys_create_file(struct subsystem * , struct subsys_attribute *);
+extern int __must_check subsys_create_file(struct subsystem * ,
+ struct subsys_attribute *);
#if defined(CONFIG_HOTPLUG)
void kobject_uevent(struct kobject *kobj, enum kobject_action action);
#include <linux/types.h>
#include <linux/ioport.h>
#include <linux/list.h>
+#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/device.h>
int (*probe) (struct pci_dev *dev, const struct pci_device_id *id); /* New device inserted */
void (*remove) (struct pci_dev *dev); /* Device removed (NULL if not a hot-plug capable driver) */
int (*suspend) (struct pci_dev *dev, pm_message_t state); /* Device suspended */
+ int (*suspend_late) (struct pci_dev *dev, pm_message_t state);
+ int (*resume_early) (struct pci_dev *dev);
int (*resume) (struct pci_dev *dev); /* Device woken up */
int (*enable_wake) (struct pci_dev *dev, pci_power_t state, int enable); /* Enable wake event */
void (*shutdown) (struct pci_dev *dev);
extern struct list_head pci_devices; /* list of all devices */
void pcibios_fixup_bus(struct pci_bus *);
-int pcibios_enable_device(struct pci_dev *, int mask);
+int __must_check pcibios_enable_device(struct pci_dev *, int mask);
char *pcibios_setup (char *str);
/* Used only when drivers/pci/setup.c is used */
return pci_bus_write_config_dword (dev->bus, dev->devfn, where, val);
}
-int pci_enable_device(struct pci_dev *dev);
-int pci_enable_device_bars(struct pci_dev *dev, int mask);
+int __must_check pci_enable_device(struct pci_dev *dev);
+int __must_check pci_enable_device_bars(struct pci_dev *dev, int mask);
void pci_disable_device(struct pci_dev *dev);
void pci_set_master(struct pci_dev *dev);
#define HAVE_PCI_SET_MWI
-int pci_set_mwi(struct pci_dev *dev);
+int __must_check pci_set_mwi(struct pci_dev *dev);
void pci_clear_mwi(struct pci_dev *dev);
void pci_intx(struct pci_dev *dev, int enable);
int pci_set_dma_mask(struct pci_dev *dev, u64 mask);
int pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask);
void pci_update_resource(struct pci_dev *dev, struct resource *res, int resno);
-int pci_assign_resource(struct pci_dev *dev, int i);
-int pci_assign_resource_fixed(struct pci_dev *dev, int i);
+int __must_check pci_assign_resource(struct pci_dev *dev, int i);
+int __must_check pci_assign_resource_fixed(struct pci_dev *dev, int i);
void pci_restore_bars(struct pci_dev *dev);
/* ROM control related routines */
void pci_fixup_irqs(u8 (*)(struct pci_dev *, u8 *),
int (*)(struct pci_dev *, u8, u8));
#define HAVE_PCI_REQ_REGIONS 2
-int pci_request_regions(struct pci_dev *, const char *);
+int __must_check pci_request_regions(struct pci_dev *, const char *);
void pci_release_regions(struct pci_dev *);
-int pci_request_region(struct pci_dev *, int, const char *);
+int __must_check pci_request_region(struct pci_dev *, int, const char *);
void pci_release_region(struct pci_dev *, int);
/* drivers/pci/bus.c */
-int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
- resource_size_t size, resource_size_t align,
- resource_size_t min, unsigned int type_mask,
- void (*alignf)(void *, struct resource *,
- resource_size_t, resource_size_t),
- void *alignf_data);
+int __must_check pci_bus_alloc_resource(struct pci_bus *bus,
+ struct resource *res, resource_size_t size,
+ resource_size_t align, resource_size_t min,
+ unsigned int type_mask,
+ void (*alignf)(void *, struct resource *,
+ resource_size_t, resource_size_t),
+ void *alignf_data);
void pci_enable_bridges(struct pci_bus *bus);
/* Proper probing supporting hot-pluggable devices */
-int __pci_register_driver(struct pci_driver *, struct module *);
-static inline int pci_register_driver(struct pci_driver *driver)
+int __must_check __pci_register_driver(struct pci_driver *, struct module *);
+static inline int __must_check pci_register_driver(struct pci_driver *driver)
{
return __pci_register_driver(driver, THIS_MODULE);
}
int (*remove)(struct platform_device *);
void (*shutdown)(struct platform_device *);
int (*suspend)(struct platform_device *, pm_message_t state);
+ int (*suspend_late)(struct platform_device *, pm_message_t state);
+ int (*resume_early)(struct platform_device *);
int (*resume)(struct platform_device *);
struct device_driver driver;
};
} pm_message_t;
/*
- * There are 4 important states driver can be in:
- * ON -- driver is working
- * FREEZE -- stop operations and apply whatever policy is applicable to a
- * suspended driver of that class, freeze queues for block like IDE
- * does, drop packets for ethernet, etc... stop DMA engine too etc...
- * so a consistent image can be saved; but do not power any hardware
- * down.
- * SUSPEND - like FREEZE, but hardware is doing as much powersaving as
- * possible. Roughly pci D3.
+ * Several driver power state transitions are externally visible, affecting
+ * the state of pending I/O queues and (for drivers that touch hardware)
+ * interrupts, wakeups, DMA, and other hardware state. There may also be
+ * internal transitions to various low power modes, which are transparent
+ * to the rest of the driver stack (such as a driver that's ON gating off
+ * clocks which are not in active use).
*
- * Unfortunately, current drivers only recognize numeric values 0 (ON) and 3
- * (SUSPEND). We'll need to fix the drivers. So yes, putting 3 to all different
- * defines is intentional, and will go away as soon as drivers are fixed. Also
- * note that typedef is neccessary, we'll probably want to switch to
- * typedef struct pm_message_t { int event; int flags; } pm_message_t
- * or something similar soon.
+ * One transition is triggered by resume(), after a suspend() call; the
+ * message is implicit:
+ *
+ * ON Driver starts working again, responding to hardware events
+ * and software requests. The hardware may have gone through
+ * a power-off reset, or it may have maintained state from the
+ * previous suspend() which the driver will rely on while
+ * resuming. On most platforms, there are no restrictions on
+ * availability of resources like clocks during resume().
+ *
+ * Other transitions are triggered by messages sent using suspend(). All
+ * these transitions quiesce the driver, so that I/O queues are inactive.
+ * That commonly entails turning off IRQs and DMA; there may be rules
+ * about how to quiesce that are specific to the bus or the device's type.
+ * (For example, network drivers mark the link state.) Other details may
+ * differ according to the message:
+ *
+ * SUSPEND Quiesce, enter a low power device state appropriate for
+ * the upcoming system state (such as PCI_D3hot), and enable
+ * wakeup events as appropriate.
+ *
+ * FREEZE Quiesce operations so that a consistent image can be saved;
+ * but do NOT otherwise enter a low power device state, and do
+ * NOT emit system wakeup events.
+ *
+ * PRETHAW Quiesce as if for FREEZE; additionally, prepare for restoring
+ * the system from a snapshot taken after an earlier FREEZE.
+ * Some drivers will need to reset their hardware state instead
+ * of preserving it, to ensure that it's never mistaken for the
+ * state which that earlier snapshot had set up.
+ *
+ * A minimally power-aware driver treats all messages as SUSPEND, fully
+ * reinitializes its device during resume() -- whether or not it was reset
+ * during the suspend/resume cycle -- and can't issue wakeup events.
+ *
+ * More power-aware drivers may also use low power states at runtime as
+ * well as during system sleep states like PM_SUSPEND_STANDBY. They may
+ * be able to use wakeup events to exit from runtime low-power states,
+ * or from system low-power states such as standby or suspend-to-RAM.
*/
#define PM_EVENT_ON 0
#define PM_EVENT_FREEZE 1
#define PM_EVENT_SUSPEND 2
+#define PM_EVENT_PRETHAW 3
#define PMSG_FREEZE ((struct pm_message){ .event = PM_EVENT_FREEZE, })
+#define PMSG_PRETHAW ((struct pm_message){ .event = PM_EVENT_PRETHAW, })
#define PMSG_SUSPEND ((struct pm_message){ .event = PM_EVENT_SUSPEND, })
#define PMSG_ON ((struct pm_message){ .event = PM_EVENT_ON, })
extern suspend_disk_method_t pm_disk_mode;
extern int device_suspend(pm_message_t state);
+extern int device_prepare_suspend(pm_message_t state);
#define device_set_wakeup_enable(dev,val) \
((dev)->power.should_wakeup = !!(val))
#ifndef _SYSFS_H_
#define _SYSFS_H_
+#include <linux/compiler.h>
#include <asm/atomic.h>
struct kobject;
#ifdef CONFIG_SYSFS
-extern int
+extern int __must_check
sysfs_create_dir(struct kobject *);
extern void
sysfs_remove_dir(struct kobject *);
-extern int
+extern int __must_check
sysfs_rename_dir(struct kobject *, const char *new_name);
-extern int
+extern int __must_check
sysfs_create_file(struct kobject *, const struct attribute *);
-extern int
+extern int __must_check
sysfs_update_file(struct kobject *, const struct attribute *);
-extern int
+extern int __must_check
sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode);
extern void
sysfs_remove_file(struct kobject *, const struct attribute *);
-extern int
+extern int __must_check
sysfs_create_link(struct kobject * kobj, struct kobject * target, const char * name);
extern void
sysfs_remove_link(struct kobject *, const char * name);
-int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr);
-int sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr);
+int __must_check sysfs_create_bin_file(struct kobject *kobj,
+ struct bin_attribute *attr);
+void sysfs_remove_bin_file(struct kobject *kobj, struct bin_attribute *attr);
-int sysfs_create_group(struct kobject *, const struct attribute_group *);
+int __must_check sysfs_create_group(struct kobject *,
+ const struct attribute_group *);
void sysfs_remove_group(struct kobject *, const struct attribute_group *);
void sysfs_notify(struct kobject * k, char *dir, char *attr);
+extern int __must_check sysfs_init(void);
+
#else /* CONFIG_SYSFS */
static inline int sysfs_create_dir(struct kobject * k)
{
}
+static inline int __must_check sysfs_init(void)
+{
+ return 0;
+}
+
#endif /* CONFIG_SYSFS */
#endif /* _SYSFS_H_ */
extern struct video_device* video_devdata(struct file*);
#define to_video_device(cd) container_of(cd, struct video_device, class_dev)
-static inline int
+static inline int __must_check
video_device_create_file(struct video_device *vfd,
struct class_device_attribute *attr)
{
#include <linux/security.h>
#include <linux/delay.h>
#include <linux/mount.h>
+#include <linux/device.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_fs_sb.h>
ssleep(root_delay);
}
+ /* wait for the known devices to complete their probing */
+ while (driver_probe_done() != 0)
+ msleep(100);
+
md_run_setup();
if (saved_root_name[0]) {
CAUTION: this option will cause your machine's real-time clock to be
set to an invalid time after a resume.
+config PM_SYSFS_DEPRECATED
+ bool "Driver model /sys/devices/.../power/state files (DEPRECATED)"
+ depends on PM && SYSFS
+ default n
+ help
+ The driver model started out with a sysfs file intended to provide
+ a userspace hook for device power management. This feature has never
+ worked very well, except for limited testing purposes, and so it will
+ be removed. It's not clear that a generic mechanism could really
+ handle the wide variability of device power states; any replacements
+ are likely to be bus or driver specific.
config SOFTWARE_SUSPEND
bool "Software Suspend"
}
/**
- * pm_suspend_disk - The granpappy of power management.
+ * pm_suspend_disk - The granpappy of hibernation power management.
*
* If we're going through the firmware, then get it over with quickly.
*
pr_debug("PM: Preparing devices for restore.\n");
- if ((error = device_suspend(PMSG_FREEZE))) {
+ if ((error = device_suspend(PMSG_PRETHAW))) {
printk("Some devices failed to suspend\n");
swsusp_free();
goto Thaw;
restore_processor_state();
Restore_highmem:
restore_highmem();
+ /* NOTE: device_power_up() is just a resume() for devices
+ * that suspended with irqs off ... no overall powerup.
+ */
device_power_up();
Enable_irqs:
local_irq_enable();
int swsusp_resume(void)
{
int error;
+
local_irq_disable();
- if (device_power_down(PMSG_FREEZE))
+ /* NOTE: device_power_down() is just a suspend() with irqs off;
+ * it has no special "power things down" semantics
+ */
+ if (device_power_down(PMSG_PRETHAW))
printk(KERN_ERR "Some devices failed to power down, very bad\n");
/* We'll ignore saved state, but this gets preempt count (etc) right */
save_processor_state();
snapshot_free_unused_memory(&data->handle);
down(&pm_sem);
pm_prepare_console();
- error = device_suspend(PMSG_FREEZE);
+ error = device_suspend(PMSG_PRETHAW);
if (!error) {
error = swsusp_resume();
device_resume();
operations. This is useful for identifying long delays
in kernel startup.
+config ENABLE_MUST_CHECK
+ bool "Enable __must_check logic"
+ default y
+ help
+ Enable the __must_check logic in the kernel build. Disable this to
+ suppress the "warning: ignoring return value of 'foo', declared with
+ attribute warn_unused_result" messages.
config MAGIC_SYSRQ
bool "Magic SysRq key"
static void klist_release(struct kref * kref)
{
struct klist_node * n = container_of(kref, struct klist_node, n_ref);
- void (*put)(struct klist_node *) = n->n_klist->put;
+
list_del(&n->n_node);
complete(&n->n_removed);
n->n_klist = NULL;
- if (put)
- put(n);
}
static int klist_dec_and_del(struct klist_node * n)
void klist_del(struct klist_node * n)
{
struct klist * k = n->n_klist;
+ void (*put)(struct klist_node *) = k->put;
spin_lock(&k->k_lock);
- klist_dec_and_del(n);
+ if (!klist_dec_and_del(n))
+ put = NULL;
spin_unlock(&k->k_lock);
+ if (put)
+ put(n);
}
EXPORT_SYMBOL_GPL(klist_del);
void klist_remove(struct klist_node * n)
{
- struct klist * k = n->n_klist;
- spin_lock(&k->k_lock);
- klist_dec_and_del(n);
- spin_unlock(&k->k_lock);
+ klist_del(n);
wait_for_completion(&n->n_removed);
}
struct klist_node * klist_next(struct klist_iter * i)
{
struct list_head * next;
+ struct klist_node * lnode = i->i_cur;
struct klist_node * knode = NULL;
+ void (*put)(struct klist_node *) = i->i_klist->put;
spin_lock(&i->i_klist->k_lock);
- if (i->i_cur) {
- next = i->i_cur->n_node.next;
- klist_dec_and_del(i->i_cur);
+ if (lnode) {
+ next = lnode->n_node.next;
+ if (!klist_dec_and_del(lnode))
+ put = NULL;
} else
next = i->i_head->next;
}
i->i_cur = knode;
spin_unlock(&i->i_klist->k_lock);
+ if (put && lnode)
+ put(lnode);
return knode;
}
struct kobject *kobject_add_dir(struct kobject *parent, const char *name)
{
struct kobject *k;
+ int ret;
if (!parent)
return NULL;
k->parent = parent;
k->ktype = &dir_ktype;
kobject_set_name(k, name);
- kobject_register(k);
+ ret = kobject_register(k);
+ if (ret < 0) {
+ printk(KERN_WARNING "kobject_add_dir: "
+ "kobject_register error: %d\n", ret);
+ kobject_del(k);
+ return NULL;
+ }
return k;
}
projects / powerpc.git / commitdiff