]> git.baikalelectronics.ru Git - kernel.git/commit
x86/sysfb_efi: Fix valid BAR address range check
authorWang YanQing <udknight@gmail.com>
Thu, 5 May 2016 13:14:21 +0000 (14:14 +0100)
committerIngo Molnar <mingo@kernel.org>
Thu, 5 May 2016 14:01:00 +0000 (16:01 +0200)
commitf38626067515cf0d474b68a6979871bdc2288937
treefc70c2fe4fbb5b974eb7ec07eeec5f409b2fca0c
parent29a88e0d46d089b8f6d4980e966b8e299d484244
x86/sysfb_efi: Fix valid BAR address range check

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: <stable@vger.kernel.org>
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>
arch/x86/kernel/sysfb_efi.c