x86/efi: Fix multiple GOP device support

When multiple GOP devices exists, but none of them implements
ConOut, the code should just choose the first GOP (according to
the comments). But currently 'fb_base' will refer to the last GOP,
while other parameters to the first GOP, which will likely
result in a garbled display.

I can reliably reproduce this bug using my ASRock Z87M Extreme4
motherboard with CSM and integrated GPU disabled, and two PCIe
video cards (NVidia GT640 and GTX980), booting from efi-stub
(booting from grub works fine).  On the primary display the
ASRock logo remains and on the secondary screen it is garbled
up completely.

Signed-off-by: Kővágó, Zoltán <DirtY.iCE.hu@gmail.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Cc: <stable@vger.kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1444659236-24837-2-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index ee1b6d346b983ad196a003dcb47c7a1de439eb3b..db51c1f27446157001cedc87bdd38b551e2f1844 100644 (file)
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -667,6 +667,7 @@ setup_gop32(struct screen_info *si, efi_guid_t *proto,
                bool conout_found = false;
                void *dummy = NULL;
                u32 h = handles[i];
+               u32 current_fb_base;
 
                status = efi_call_early(handle_protocol, h,
                                        proto, (void **)&gop32);
@@ -678,7 +679,7 @@ setup_gop32(struct screen_info *si, efi_guid_t *proto,
                if (status == EFI_SUCCESS)
                        conout_found = true;
 
-               status = __gop_query32(gop32, &info, &size, &fb_base);
+               status = __gop_query32(gop32, &info, &size, &current_fb_base);
                if (status == EFI_SUCCESS && (!first_gop || conout_found)) {
                        /*
                         * Systems that use the UEFI Console Splitter may
@@ -692,6 +693,7 @@ setup_gop32(struct screen_info *si, efi_guid_t *proto,
                        pixel_format = info->pixel_format;
                        pixel_info = info->pixel_information;
                        pixels_per_scan_line = info->pixels_per_scan_line;
+                       fb_base = current_fb_base;
 
                        /*
                         * Once we've found a GOP supporting ConOut,
@@ -770,6 +772,7 @@ setup_gop64(struct screen_info *si, efi_guid_t *proto,
                bool conout_found = false;
                void *dummy = NULL;
                u64 h = handles[i];
+               u32 current_fb_base;
 
                status = efi_call_early(handle_protocol, h,
                                        proto, (void **)&gop64);
@@ -781,7 +784,7 @@ setup_gop64(struct screen_info *si, efi_guid_t *proto,
                if (status == EFI_SUCCESS)
                        conout_found = true;
 
-               status = __gop_query64(gop64, &info, &size, &fb_base);
+               status = __gop_query64(gop64, &info, &size, &current_fb_base);
                if (status == EFI_SUCCESS && (!first_gop || conout_found)) {
                        /*
                         * Systems that use the UEFI Console Splitter may
@@ -795,6 +798,7 @@ setup_gop64(struct screen_info *si, efi_guid_t *proto,
                        pixel_format = info->pixel_format;
                        pixel_info = info->pixel_information;
                        pixels_per_scan_line = info->pixels_per_scan_line;
+                       fb_base = current_fb_base;
 
                        /*
                         * Once we've found a GOP supporting ConOut,