From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Januszewski Subject: [PATCH v3] fbdev: ignore VESA modes if framebuffer does not support them Date: Sun, 28 Sep 2008 14:54:15 +0200 Message-ID: <20080928125414.GA27703@spock.one.pl> Reply-To: spock@gentoo.org Mime-Version: 1.0 Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-kernel@vger.kernel.org Cc: linux-fbdev-devel@lists.sourceforge.net, krzysztof.h1@poczta.fm, akpm@linux-foundation.org, bonbons@linux-vserver.org, hpa@zytor.com Currently, it is possible to set a graphics VESA mode at boot time via the vga= parameter even when no framebuffer driver supporting this is configured. This could lead to the system booting with a black screen, without a usable console. Fix this problem by only allowing to set graphics modes at boot time if a supporting framebuffer driver is configured. Signed-off-by: Michal Januszewski Acked-by: Krzysztof Helt --- This version of the patch replaces the FB_SUPPORTS_BOOT_VESA macro from screen-info.h with a config option in drivers/video/Kconfig. diff --git a/arch/x86/boot/video-vesa.c b/arch/x86/boot/video-vesa.c index 401ad99..47e5080 100644 --- a/arch/x86/boot/video-vesa.c +++ b/arch/x86/boot/video-vesa.c @@ -88,14 +88,11 @@ static int vesa_probe(void) (vminfo.memory_layout == 4 || vminfo.memory_layout == 6) && vminfo.memory_planes == 1) { -#ifdef CONFIG_FB +#ifdef CONFIG_FB_BOOT_VESA_SUPPORT /* Graphics mode, color, linear frame buffer supported. Only register the mode if if framebuffer is configured, however, - otherwise the user will be left without a screen. - We don't require CONFIG_FB_VESA, however, since - some of the other framebuffer drivers can use - this mode-setting, too. */ + otherwise the user will be left without a screen. */ mi = GET_HEAP(struct mode_info, 1); mi->mode = mode + VIDEO_FIRST_VESA; mi->depth = vminfo.bpp; @@ -133,10 +130,12 @@ static int vesa_set_mode(struct mode_info *mode) if ((vminfo.mode_attr & 0x15) == 0x05) { /* It's a supported text mode */ is_graphic = 0; +#ifdef CONFIG_FB_BOOT_VESA_SUPPORT } else if ((vminfo.mode_attr & 0x99) == 0x99) { /* It's a graphics mode with linear frame buffer */ is_graphic = 1; vesa_mode |= 0x4000; /* Request linear frame buffer */ +#endif } else { return -1; /* Invalid mode */ } diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig index 70d135e..651249d 100644 --- a/drivers/video/Kconfig +++ b/drivers/video/Kconfig @@ -76,6 +76,14 @@ config FB_DDC select I2C default n +config FB_BOOT_VESA_SUPPORT + bool + depends on FB + default n + ---help--- + If true, at least one selected framebuffer driver can take advantage + of VESA video modes set at an early boot stage via the vga= parameter. + config FB_CFB_FILLRECT tristate depends on FB @@ -679,6 +687,7 @@ config FB_VESA select FB_CFB_COPYAREA select FB_CFB_IMAGEBLIT select VIDEO_SELECT + select FB_BOOT_VESA_SUPPORT help This is the frame buffer device driver for generic VESA 2.0 compliant graphic cards. The older VESA 1.2 cards are not supported. @@ -702,6 +711,7 @@ config FB_IMAC select FB_CFB_FILLRECT select FB_CFB_COPYAREA select FB_CFB_IMAGEBLIT + select FB_BOOT_VESA_SUPPORT help This is the frame buffer device driver for the Intel-based Macintosh @@ -1124,6 +1134,7 @@ config FB_INTEL select FB_CFB_FILLRECT select FB_CFB_COPYAREA select FB_CFB_IMAGEBLIT + select FB_BOOT_VESA_SUPPORT help This driver supports the on-board graphics built in to the Intel 830M/845G/852GM/855GM/865G/915G/915GM/945G/945GM/965G/965GM chipsets. @@ -1476,6 +1487,7 @@ config FB_SIS select FB_CFB_FILLRECT select FB_CFB_COPYAREA select FB_CFB_IMAGEBLIT + select FB_BOOT_VESA_SUPPORT help This is the frame buffer device driver for the SiS 300, 315, 330 and 340 series as well as XGI V3XT, V5, V8, Z7 graphics chipsets.