diff options
| author | Uwe Kleine-König <u.kleine-koenig@pengutronix.de> | 2010-11-24 12:57:14 -0800 |
|---|---|---|
| committer | Paul Gortmaker <paul.gortmaker@windriver.com> | 2011-04-17 16:15:52 -0400 |
| commit | 5c0f71147d9b5623db9353002605c9c648870e8d (patch) | |
| tree | 551ed0ec1af41e6da5f27b84dfca826edf544027 /drivers | |
| parent | 1c215bfe11bc1837af11df453a4fa586dafad56b (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: Paul Gortmaker <paul.gortmaker@windriver.com>
Diffstat (limited to 'drivers')
| -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 e207810bba3c..08703299ef61 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -197,12 +197,12 @@ 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; } @@ -211,12 +211,12 @@ 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; } |