From 98a3c781057fa43494e7e8b39d639e93fca0ecbf Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Thu, 31 Aug 2006 14:04:34 +1000 Subject: [PATCH] fbdev: Fix crashes in various fbdev's blank routines The backlight changes that went in had a bug where they could cause the kernel to access an unitialized pointer when blanking if there is no backlight control on a machine. The bug affects atyfb, aty128fb, nvidiafb and rivafb. radeonfb seems to be ok. This fixes it. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Linus Torvalds --- drivers/video/riva/fbdev.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'drivers/video/riva') diff --git a/drivers/video/riva/fbdev.c b/drivers/video/riva/fbdev.c index 76fc9d355eb7..90363943bd57 100644 --- a/drivers/video/riva/fbdev.c +++ b/drivers/video/riva/fbdev.c @@ -354,6 +354,9 @@ static struct backlight_properties riva_bl_data = { static void riva_bl_set_power(struct fb_info *info, int power) { + if (info->bl_dev == NULL) + return; + mutex_lock(&info->bl_mutex); up(&info->bl_dev->sem); info->bl_dev->props->power = power; @@ -382,7 +385,7 @@ static void riva_bl_init(struct riva_par *par) bd = backlight_device_register(name, par, &riva_bl_data); if (IS_ERR(bd)) { info->bl_dev = NULL; - printk("riva: Backlight registration failed\n"); + printk(KERN_WARNING "riva: Backlight registration failed\n"); goto error; } -- cgit v1.2.1 From a930363881c225fb52824145d1ba8f1a8c447dd8 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Thu, 31 Aug 2006 21:27:54 -0700 Subject: [PATCH] backlight last round of fixes Fix some more problems (inverted use of semaphores in some places). He also moved my checks into within the protected section which is better. Signed-off-by: Michael Hanselmann Signed-off-by: Benjamin Herrenschmidt Cc: "Antonino A. Daplas" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/video/riva/fbdev.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) (limited to 'drivers/video/riva') diff --git a/drivers/video/riva/fbdev.c b/drivers/video/riva/fbdev.c index 90363943bd57..8ddb47a56b07 100644 --- a/drivers/video/riva/fbdev.c +++ b/drivers/video/riva/fbdev.c @@ -354,14 +354,15 @@ static struct backlight_properties riva_bl_data = { static void riva_bl_set_power(struct fb_info *info, int power) { - if (info->bl_dev == NULL) - return; - mutex_lock(&info->bl_mutex); - up(&info->bl_dev->sem); - info->bl_dev->props->power = power; - __riva_bl_update_status(info->bl_dev); - down(&info->bl_dev->sem); + + if (info->bl_dev) { + down(&info->bl_dev->sem); + info->bl_dev->props->power = power; + __riva_bl_update_status(info->bl_dev); + up(&info->bl_dev->sem); + } + mutex_unlock(&info->bl_mutex); } @@ -396,11 +397,11 @@ static void riva_bl_init(struct riva_par *par) 0x534 * FB_BACKLIGHT_MAX / MAX_LEVEL); mutex_unlock(&info->bl_mutex); - up(&bd->sem); + down(&bd->sem); bd->props->brightness = riva_bl_data.max_brightness; bd->props->power = FB_BLANK_UNBLANK; bd->props->update_status(bd); - down(&bd->sem); + up(&bd->sem); #ifdef CONFIG_PMAC_BACKLIGHT mutex_lock(&pmac_backlight_mutex); -- cgit v1.2.1