From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id AC61567B53 for ; Thu, 31 Aug 2006 14:05:40 +1000 (EST) Subject: [PATCH] fbdev: Fix crashes in various fbdev's blank routines From: Benjamin Herrenschmidt To: Andrew Morton , Linus Torvalds Content-Type: text/plain Date: Thu, 31 Aug 2006 14:04:34 +1000 Message-Id: <1156997075.12526.104.camel@localhost.localdomain> Mime-Version: 1.0 Cc: linuxppc-dev list , Linux Fbdev development list , Olaf Hering List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , The backlight changes that went in 2.6.18 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 --- This is a 2.6.18 regression, please merge before release ! It breaks a number of non-laptop powermacs (among others I suppose). Index: linux-work/drivers/video/aty/aty128fb.c =================================================================== --- linux-work.orig/drivers/video/aty/aty128fb.c 2006-08-17 09:26:21.000000000 +1000 +++ linux-work/drivers/video/aty/aty128fb.c 2006-08-31 13:56:11.000000000 +1000 @@ -1800,6 +1800,9 @@ static struct backlight_properties aty12 static void aty128_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; @@ -1828,7 +1831,7 @@ static void aty128_bl_init(struct aty128 bd = backlight_device_register(name, par, &aty128_bl_data); if (IS_ERR(bd)) { info->bl_dev = NULL; - printk("aty128: Backlight registration failed\n"); + printk(KERN_WARNING "aty128: Backlight registration failed\n"); goto error; } Index: linux-work/drivers/video/aty/atyfb_base.c =================================================================== --- linux-work.orig/drivers/video/aty/atyfb_base.c 2006-08-17 09:26:21.000000000 +1000 +++ linux-work/drivers/video/aty/atyfb_base.c 2006-08-31 13:55:43.000000000 +1000 @@ -2199,6 +2199,9 @@ static struct backlight_properties aty_b 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 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; } Index: linux-work/drivers/video/nvidia/nv_backlight.c =================================================================== --- linux-work.orig/drivers/video/nvidia/nv_backlight.c 2006-08-17 09:26:22.000000000 +1000 +++ linux-work/drivers/video/nvidia/nv_backlight.c 2006-08-31 13:58:47.000000000 +1000 @@ -112,6 +112,8 @@ static struct backlight_properties nvidi void nvidia_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; @@ -140,7 +142,7 @@ void nvidia_bl_init(struct nvidia_par *p bd = backlight_device_register(name, par, &nvidia_bl_data); if (IS_ERR(bd)) { info->bl_dev = NULL; - printk("nvidia: Backlight registration failed\n"); + printk(KERN_WARNING "nvidia: Backlight registration failed\n"); goto error; } Index: linux-work/drivers/video/riva/fbdev.c =================================================================== --- linux-work.orig/drivers/video/riva/fbdev.c 2006-08-17 09:26:22.000000000 +1000 +++ linux-work/drivers/video/riva/fbdev.c 2006-08-31 13:58:49.000000000 +1000 @@ -354,6 +354,9 @@ static struct backlight_properties riva_ 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 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; }