This is a note to let you know that I've just added the patch titled
backlight: grab ops_lock before testing bd->ops
to the 2.6.32-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
backlight-grab-ops_lock-before-testing-bd-ops.patch
and it can be found in the queue-2.6.32 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
From d1d73578e053b981c3611e5a211534290d24a5eb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <[email protected]>
Date: Wed, 24 Nov 2010 12:57:14 -0800
Subject: backlight: grab ops_lock before testing bd->ops
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From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <[email protected]>
commit d1d73578e053b981c3611e5a211534290d24a5eb upstream.
According to the comment describing ops_lock in the definition of struct
backlight_device and when comparing with other functions in backlight.c
the mutex must be hold when checking ops to be non-NULL.
Fixes a problem added by c835ee7f4154992e6 ("backlight: Add suspend/resume
support to the backlight core") in Jan 2009.
Signed-off-by: Uwe Kleine-König <[email protected]>
Acked-by: Richard Purdie <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/video/backlight/backlight.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -196,12 +196,12 @@ static int backlight_suspend(struct devi
{
struct backlight_device *bd = to_backlight_device(dev);
- if (bd->ops->options & BL_CORE_SUSPENDRESUME) {
- mutex_lock(&bd->ops_lock);
+ mutex_lock(&bd->ops_lock);
+ if (bd->ops && bd->ops->options & BL_CORE_SUSPENDRESUME) {
bd->props.state |= BL_CORE_SUSPENDED;
backlight_update_status(bd);
- mutex_unlock(&bd->ops_lock);
}
+ mutex_unlock(&bd->ops_lock);
return 0;
}
@@ -210,12 +210,12 @@ static int backlight_resume(struct devic
{
struct backlight_device *bd = to_backlight_device(dev);
- if (bd->ops->options & BL_CORE_SUSPENDRESUME) {
- mutex_lock(&bd->ops_lock);
+ mutex_lock(&bd->ops_lock);
+ if (bd->ops && bd->ops->options & BL_CORE_SUSPENDRESUME) {
bd->props.state &= ~BL_CORE_SUSPENDED;
backlight_update_status(bd);
- mutex_unlock(&bd->ops_lock);
}
+ mutex_unlock(&bd->ops_lock);
return 0;
}
Patches currently in stable-queue which might be from
[email protected] are
queue-2.6.32/backlight-grab-ops_lock-before-testing-bd-ops.patch
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