[patch 43/47] serial: fix enable_irq_wake/disable_irq_wakeimbalance in serial_core.c

[Greg KH]

-stable review patch.  If anyone has any objections, please let us know.

------------------
From: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>

commit 03a74dcc7eebe6edd778317e82fafdf71e68488c in mainline.

enable_irq_wake() and disable_irq_wake() need to be balanced.  However,
serial_core.c calls these for different conditions during the suspend and
resume functions...

This is causing a regular WARN_ON() as found at
http://www.kerneloops.org/search.php?search=set_irq_wake

This patch makes the conditions for triggering the _wake enable/disable
sequence identical.

Signed-off-by: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 drivers/serial/serial_core.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -2022,6 +2022,8 @@ int uart_suspend_port(struct uart_driver
 int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
 {
 	struct uart_state *state = drv->state + port->line;
+	struct device *tty_dev;
+	struct uart_match match = {port, drv};
 
 	mutex_lock(&state->mutex);
 
@@ -2031,7 +2033,8 @@ int uart_resume_port(struct uart_driver 
 		return 0;
 	}
 
-	if (!port->suspended) {
+	tty_dev = device_find_child(port->dev, &match, serial_match_port);
+	if (!port->suspended && device_may_wakeup(tty_dev)) {
 		disable_irq_wake(port->irq);
 		mutex_unlock(&state->mutex);
 		return 0;

-- 
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