X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=drivers%2Fserial%2Fserial_core.c;h=17839e753e4cfb1fb550832d8613b0ec579c83ef;hb=b0c51b7d650d5109c8e71e19d5e7ce9b71af7dff;hp=0717abfdae06f1eed3d132cdbd7e7a3cced60858;hpb=078a9b0388619c6c4c347458c6861833b911313b;p=powerpc.git

diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 0717abfdae..17839e753e 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -71,6 +71,11 @@ static void uart_change_pm(struct uart_state *state, int pm_state);
 void uart_write_wakeup(struct uart_port *port)
 {
 	struct uart_info *info = port->info;
+	/*
+	 * This means you called this function _after_ the port was
+	 * closed.  No cookie for you.
+	 */
+	BUG_ON(!info);
 	tasklet_schedule(&info->tlet);
 }
 
@@ -471,14 +476,26 @@ static void uart_flush_chars(struct tty_struct *tty)
 }
 
 static int
-uart_write(struct tty_struct *tty, const unsigned char * buf, int count)
+uart_write(struct tty_struct *tty, const unsigned char *buf, int count)
 {
 	struct uart_state *state = tty->driver_data;
-	struct uart_port *port = state->port;
-	struct circ_buf *circ = &state->info->xmit;
+	struct uart_port *port;
+	struct circ_buf *circ;
 	unsigned long flags;
 	int c, ret = 0;
 
+	/*
+	 * This means you called this function _after_ the port was
+	 * closed.  No cookie for you.
+	 */
+	if (!state || !state->info) {
+		WARN_ON(1);
+		return -EL3HLT;
+	}
+
+	port = state->port;
+	circ = &state->info->xmit;
+
 	if (!circ->buf)
 		return 0;
 
@@ -521,6 +538,15 @@ static void uart_flush_buffer(struct tty_struct *tty)
 	struct uart_port *port = state->port;
 	unsigned long flags;
 
+	/*
+	 * This means you called this function _after_ the port was
+	 * closed.  No cookie for you.
+	 */
+	if (!state || !state->info) {
+		WARN_ON(1);
+		return;
+	}
+
 	DPRINTK("uart_flush_buffer(%d) called\n", tty->index);
 
 	spin_lock_irqsave(&port->lock, flags);
@@ -1474,20 +1500,18 @@ uart_block_til_ready(struct file *filp, struct uart_state *state)
 static struct uart_state *uart_get(struct uart_driver *drv, int line)
 {
 	struct uart_state *state;
+	int ret = 0;
 
-	mutex_lock(&port_mutex);
 	state = drv->state + line;
 	if (mutex_lock_interruptible(&state->mutex)) {
-		state = ERR_PTR(-ERESTARTSYS);
-		goto out;
+		ret = -ERESTARTSYS;
+		goto err;
 	}
 
 	state->count++;
-	if (!state->port) {
-		state->count--;
-		mutex_unlock(&state->mutex);
-		state = ERR_PTR(-ENXIO);
-		goto out;
+	if (!state->port || state->port->flags & UPF_DEAD) {
+		ret = -ENXIO;
+		goto err_unlock;
 	}
 
 	if (!state->info) {
@@ -1505,15 +1529,17 @@ static struct uart_state *uart_get(struct uart_driver *drv, int line)
 			tasklet_init(&state->info->tlet, uart_tasklet_action,
 				     (unsigned long)state);
 		} else {
-			state->count--;
-			mutex_unlock(&state->mutex);
-			state = ERR_PTR(-ENOMEM);
+			ret = -ENOMEM;
+			goto err_unlock;
 		}
 	}
-
- out:
-	mutex_unlock(&port_mutex);
 	return state;
+
+ err_unlock:
+	state->count--;
+	mutex_unlock(&state->mutex);
+ err:
+	return ERR_PTR(ret);
 }
 
 /*
@@ -1728,6 +1754,27 @@ static int uart_read_proc(char *page, char **start, off_t off,
 #endif
 
 #ifdef CONFIG_SERIAL_CORE_CONSOLE
+/*
+ *	uart_console_write - write a console message to a serial port
+ *	@port: the port to write the message
+ *	@s: array of characters
+ *	@count: number of characters in string to write
+ *	@write: function to write character to port
+ */
+void uart_console_write(struct uart_port *port, const char *s,
+			unsigned int count,
+			void (*putchar)(struct uart_port *, int))
+{
+	unsigned int i;
+
+	for (i = 0; i < count; i++, s++) {
+		if (*s == '\n')
+			putchar(port, '\r');
+		putchar(port, *s);
+	}
+}
+EXPORT_SYMBOL_GPL(uart_console_write);
+
 /*
  *	Check whether an invalid uart number has been specified, and
  *	if so, search for the first available port that does have
@@ -1860,9 +1907,12 @@ uart_set_options(struct uart_port *port, struct console *co,
 static void uart_change_pm(struct uart_state *state, int pm_state)
 {
 	struct uart_port *port = state->port;
-	if (port->ops->pm)
-		port->ops->pm(port, pm_state, state->pm_state);
-	state->pm_state = pm_state;
+
+	if (state->pm_state != pm_state) {
+		if (port->ops->pm)
+			port->ops->pm(port, pm_state, state->pm_state);
+		state->pm_state = pm_state;
+	}
 }
 
 int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
@@ -2038,45 +2088,6 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 	}
 }
 
-/*
- * This reverses the effects of uart_configure_port, hanging up the
- * port before removal.
- */
-static void
-uart_unconfigure_port(struct uart_driver *drv, struct uart_state *state)
-{
-	struct uart_port *port = state->port;
-	struct uart_info *info = state->info;
-
-	if (info && info->tty)
-		tty_vhangup(info->tty);
-
-	mutex_lock(&state->mutex);
-
-	state->info = NULL;
-
-	/*
-	 * Free the port IO and memory resources, if any.
-	 */
-	if (port->type != PORT_UNKNOWN)
-		port->ops->release_port(port);
-
-	/*
-	 * Indicate that there isn't a port here anymore.
-	 */
-	port->type = PORT_UNKNOWN;
-
-	/*
-	 * Kill the tasklet, and free resources.
-	 */
-	if (info) {
-		tasklet_kill(&info->tlet);
-		kfree(info);
-	}
-
-	mutex_unlock(&state->mutex);
-}
-
 static struct tty_operations uart_ops = {
 	.open		= uart_open,
 	.close		= uart_close,
@@ -2223,6 +2234,7 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
 	state = drv->state + port->line;
 
 	mutex_lock(&port_mutex);
+	mutex_lock(&state->mutex);
 	if (state->port) {
 		ret = -EINVAL;
 		goto out;
@@ -2237,7 +2249,7 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
 	 * If this port is a console, then the spinlock is already
 	 * initialised.
 	 */
-	if (!uart_console(port))
+	if (!(uart_console(port) && (port->cons->flags & CON_ENABLED)))
 		spin_lock_init(&port->lock);
 
 	uart_configure_port(drv, state, port);
@@ -2257,7 +2269,13 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
 	    port->cons && !(port->cons->flags & CON_ENABLED))
 		register_console(port->cons);
 
+	/*
+	 * Ensure UPF_DEAD is not set.
+	 */
+	port->flags &= ~UPF_DEAD;
+
  out:
+	mutex_unlock(&state->mutex);
 	mutex_unlock(&port_mutex);
 
 	return ret;
@@ -2275,6 +2293,7 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)
 {
 	struct uart_state *state = drv->state + port->line;
+	struct uart_info *info;
 
 	BUG_ON(in_interrupt());
 
@@ -2284,12 +2303,49 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)
 
 	mutex_lock(&port_mutex);
 
+	/*
+	 * Mark the port "dead" - this prevents any opens from
+	 * succeeding while we shut down the port.
+	 */
+	mutex_lock(&state->mutex);
+	port->flags |= UPF_DEAD;
+	mutex_unlock(&state->mutex);
+
 	/*
 	 * Remove the devices from devfs
 	 */
 	tty_unregister_device(drv->tty_driver, port->line);
 
-	uart_unconfigure_port(drv, state);
+	info = state->info;
+	if (info && info->tty)
+		tty_vhangup(info->tty);
+
+	/*
+	 * All users of this port should now be disconnected from
+	 * this driver, and the port shut down.  We should be the
+	 * only thread fiddling with this port from now on.
+	 */
+	state->info = NULL;
+
+	/*
+	 * Free the port IO and memory resources, if any.
+	 */
+	if (port->type != PORT_UNKNOWN)
+		port->ops->release_port(port);
+
+	/*
+	 * Indicate that there isn't a port here anymore.
+	 */
+	port->type = PORT_UNKNOWN;
+
+	/*
+	 * Kill the tasklet, and free resources.
+	 */
+	if (info) {
+		tasklet_kill(&info->tlet);
+		kfree(info);
+	}
+
 	state->port = NULL;
 	mutex_unlock(&port_mutex);