pinctrl: core: Fix regression caused by delayed work for hogs
authorTony Lindgren <tony@atomide.com>
Wed, 11 Jan 2017 22:13:34 +0000 (14:13 -0800)
committerLinus Walleij <linus.walleij@linaro.org>
Fri, 13 Jan 2017 15:25:17 +0000 (16:25 +0100)
commit950b0d91dc108f54bccca5a2f75bb46f2df63d29
tree305daab89f93b16951c6a53efc9bb002eacdefc9
parent56d9e4a76039afd504919cc5ec329fb0ce35812f
pinctrl: core: Fix regression caused by delayed work for hogs

Commit df61b366af26 ("pinctrl: core: Use delayed work for hogs") caused a
regression at least with sh-pfc that is also a GPIO controller as
noted by Geert Uytterhoeven <geert@linux-m68k.org>.

As the original pinctrl_register() has issues calling pin controller
driver functions early before the controller has finished registering,
we can't just revert commit df61b366af26. That would break the drivers
using GENERIC_PINCTRL_GROUPS or GENERIC_PINMUX_FUNCTIONS.

So let's fix the issue with the following steps as a single patch:

1. Revert the late_init parts of commit df61b366af26.

   The late_init clearly won't work and we have to just give up
   on fixing pinctrl_register() for GENERIC_PINCTRL_GROUPS and
   GENERIC_PINMUX_FUNCTIONS.

2. Split pinctrl_register() into two parts

   By splitting pinctrl_register() into pinctrl_init_controller()
   and pinctrl_create_and_start() we have better control over when
   it's safe to call pinctrl_create().

3. Introduce a new pinctrl_register_and_init() function

   As suggested by Linus Walleij <linus.walleij@linaro.org>, we
   can just introduce a new function for the controllers that need
   pinctrl_create() called later.

4. Convert the four known problem cases to use new function

   Let's convert pinctrl-imx, pinctrl-single, sh-pfc and ti-iodelay
   to use the new function to fix the issues. The rest of the drivers
   can be converted later. Let's also update Documentation/pinctrl.txt
   accordingly because of the known issues with pinctrl_register().

Fixes: df61b366af26 ("pinctrl: core: Use delayed work for hogs")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Gary Bisson <gary.bisson@boundarydevices.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Documentation/pinctrl.txt
drivers/pinctrl/core.c
drivers/pinctrl/core.h
drivers/pinctrl/freescale/pinctrl-imx.c
drivers/pinctrl/pinctrl-single.c
drivers/pinctrl/sh-pfc/pinctrl.c
drivers/pinctrl/ti/pinctrl-ti-iodelay.c
include/linux/pinctrl/pinctrl.h