From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 5 May 2016 07:03:35 -0700 From: tip-bot for Wang YanQing Message-ID: Cc: udknight@gmail.com, pjones@redhat.com, hpa@zytor.com, tglx@linutronix.de, matt@codeblueprint.co.uk, peterz@infradead.org, mingo@kernel.org, dh.herrmann@gmail.com, stable@vger.kernel.org, tomi.valkeinen@ti.com, linux-kernel@vger.kernel.org, ard.biesheuvel@linaro.org, torvalds@linux-foundation.org Reply-To: tglx@linutronix.de, hpa@zytor.com, pjones@redhat.com, udknight@gmail.com, torvalds@linux-foundation.org, ard.biesheuvel@linaro.org, tomi.valkeinen@ti.com, linux-kernel@vger.kernel.org, stable@vger.kernel.org, dh.herrmann@gmail.com, mingo@kernel.org, matt@codeblueprint.co.uk, peterz@infradead.org In-Reply-To: <1462454061-21561-2-git-send-email-matt@codeblueprint.co.uk> References: <1462454061-21561-2-git-send-email-matt@codeblueprint.co.uk> To: linux-tip-commits@vger.kernel.org Subject: [tip:efi/urgent] x86/sysfb_efi: Fix valid BAR address range check MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: Commit-ID: c10fcb14c7afd6688c7b197a814358fecf244222 Gitweb: http://git.kernel.org/tip/c10fcb14c7afd6688c7b197a814358fecf244222 Author: Wang YanQing AuthorDate: Thu, 5 May 2016 14:14:21 +0100 Committer: Ingo Molnar CommitDate: Thu, 5 May 2016 16:01:00 +0200 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 [ Rewrote changelog. ] Signed-off-by: Matt Fleming Reviewed-by: Peter Jones Cc: Cc: Ard Biesheuvel Cc: David Herrmann Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tomi Valkeinen 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 --- arch/x86/kernel/sysfb_efi.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/sysfb_efi.c b/arch/x86/kernel/sysfb_efi.c index b285d4e..5da924b 100644 --- a/arch/x86/kernel/sysfb_efi.c +++ b/arch/x86/kernel/sysfb_efi.c @@ -106,14 +106,24 @@ static int __init efifb_set_system(const struct dmi_system_id *id) continue; for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) { resource_size_t start, end; + unsigned long flags; + + flags = pci_resource_flags(dev, i); + if (!(flags & IORESOURCE_MEM)) + continue; + + if (flags & IORESOURCE_UNSET) + continue; + + if (pci_resource_len(dev, i) == 0) + continue; start = pci_resource_start(dev, i); - if (start == 0) - break; end = pci_resource_end(dev, i); if (screen_info.lfb_base >= start && screen_info.lfb_base < end) { found_bar = 1; + break; } } }