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/aty/atyfb_base.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'drivers/video/aty/atyfb_base.c') diff --git a/drivers/video/aty/atyfb_base.c b/drivers/video/aty/atyfb_base.c index 053ff63365b7..510e4ea296ed 100644 --- a/drivers/video/aty/atyfb_base.c +++ b/drivers/video/aty/atyfb_base.c @@ -2199,6 +2199,9 @@ static struct backlight_properties aty_bl_data = { static void aty_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; @@ -2223,7 +2226,7 @@ static void aty_bl_init(struct atyfb_par *par) bd = backlight_device_register(name, par, &aty_bl_data); if (IS_ERR(bd)) { info->bl_dev = NULL; - printk("aty: Backlight registration failed\n"); + printk(KERN_WARNING "aty: Backlight registration failed\n"); goto error; } -- cgit v1.2.2 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/aty/atyfb_base.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) (limited to 'drivers/video/aty/atyfb_base.c') diff --git a/drivers/video/aty/atyfb_base.c b/drivers/video/aty/atyfb_base.c index 510e4ea296ed..19a71f045784 100644 --- a/drivers/video/aty/atyfb_base.c +++ b/drivers/video/aty/atyfb_base.c @@ -2199,14 +2199,15 @@ static struct backlight_properties aty_bl_data = { static void aty_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; - __aty_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; + __aty_bl_update_status(info->bl_dev); + up(&info->bl_dev->sem); + } + mutex_unlock(&info->bl_mutex); } @@ -2237,11 +2238,11 @@ static void aty_bl_init(struct atyfb_par *par) 0xFF * FB_BACKLIGHT_MAX / MAX_LEVEL); mutex_unlock(&info->bl_mutex); - up(&bd->sem); + down(&bd->sem); bd->props->brightness = aty_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 v1.2.2