diff options
| author | Uwe Kleine-König <u.kleine-koenig@pengutronix.de> | 2010-11-24 12:57:14 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-12-09 13:27:01 -0800 |
| commit | a9386a4f6cf9c1b72862ac0aa4ffe02a22c1bd5b (patch) | |
| tree | d91b1d065e2cb0d269a38a4b7a2b4f1691376f64 | |
| parent | 20fa2a2005e86e5628941c5e23fbc4682824473e (diff) | |
backlight: grab ops_lock before testing bd->ops
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 <u.kleine-koenig@pengutronix.de>
Acked-by: Richard Purdie <rpurdie@linux.intel.com>
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>
| -rw-r--r-- | drivers/video/backlight/backlight.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index 6615ac7fa60a..5e20e6ec1719 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -196,12 +196,12 @@ static int backlight_suspend(struct device *dev, pm_message_t state) { 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 device *dev) { 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; } |