linux-stable.git/arch/x86/kernel/sysfb_efi.c, branch linux-3.12.y Linux kernel stable tree x86/sysfb_efi: Fix valid BAR address range check 2016-05-11T09:37:33+00:00 Wang YanQing udknight@gmail.com 2016-05-05T13:14:21+00:00 edfad738252de419a11a332131f8b31c776c9326 commit c10fcb14c7afd6688c7b197a814358fecf244222 upstream. The code for checking whether a BAR address range is valid will break out of the loop when a start address of 0x0 is encountered. This behaviour is wrong since by breaking out of the loop we may miss the BAR that describes the EFI frame buffer in a later iteration. Because of this bug I can't use video=efifb: boot parameter to get efifb on my new ThinkPad E550 for my old linux system hard disk with 3.10 kernel. In 3.10, efifb is the only choice due to DRM/I915 not supporting the GPU. This patch also add a trivial optimization to break out after we find the frame buffer address range without testing later BARs. Signed-off-by: Wang YanQing <udknight@gmail.com> [ Rewrote changelog. ] Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Reviewed-by: Peter Jones <pjones@redhat.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1462454061-21561-2-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit c10fcb14c7afd6688c7b197a814358fecf244222 upstream.

The code for checking whether a BAR address range is valid will break
out of the loop when a start address of 0x0 is encountered.

This behaviour is wrong since by breaking out of the loop we may miss
the BAR that describes the EFI frame buffer in a later iteration.

Because of this bug I can't use video=efifb: boot parameter to get
efifb on my new ThinkPad E550 for my old linux system hard disk with
3.10 kernel. In 3.10, efifb is the only choice due to DRM/I915 not
supporting the GPU.

This patch also add a trivial optimization to break out after we find
the frame buffer address range without testing later BARs.

Signed-off-by: Wang YanQing <udknight@gmail.com>
[ Rewrote changelog. ]
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Peter Jones <pjones@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1462454061-21561-2-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
x86: sysfb: move EFI quirks from efifb to sysfb 2013-08-02T23:17:47+00:00 David Herrmann dh.herrmann@gmail.com 2013-08-02T12:05:23+00:00 2995e506276bfdc7311eb02db8b2aa1a61a4b849 The EFI FB quirks from efifb.c are useful for simple-framebuffer devices as well. Apply them by default so we can convert efifb.c to use efi-framebuffer platform devices. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Link: http://lkml.kernel.org/r/1375445127-15480-5-git-send-email-dh.herrmann@gmail.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> 
The EFI FB quirks from efifb.c are useful for simple-framebuffer devices
as well. Apply them by default so we can convert efifb.c to use
efi-framebuffer platform devices.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Link: http://lkml.kernel.org/r/1375445127-15480-5-git-send-email-dh.herrmann@gmail.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>