From 5c1cd3ddd72f5ccd5f40e9e176a9cd69b8fd9506 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Wed, 24 Nov 2010 12:57:14 -0800 Subject: [PATCH] backlight: grab ops_lock before testing bd->ops MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Acked-by: Richard Purdie Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/video/backlight/backlight.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index 18829cf68b1b..89025e66475f 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; } -- 2.39.5