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

Greg KH
2008-06-14T00:27:00Z

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

------------------
From: Arjan van de Ven <arjan@linux.intel.com>

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@linux.intel.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
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;

--