Patch "x86/efi: Fix multiple GOP device support" has been added to the 4.2-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    x86/efi: Fix multiple GOP device support

to the 4.2-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     x86-efi-fix-multiple-gop-device-support.patch
and it can be found in the queue-4.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 8a53554e12e98d1759205afd7b8e9e2ea0936f48 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?K=C5=91v=C3=A1g=C3=B3=2C=20Zolt=C3=A1n?=
 <dirty.ice.hu@gmail.com>
Date: Mon, 12 Oct 2015 15:13:56 +0100
Subject: x86/efi: Fix multiple GOP device support
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: =?UTF-8?q?K=C5=91v=C3=A1g=C3=B3=2C=20Zolt=C3=A1n?=

commit 8a53554e12e98d1759205afd7b8e9e2ea0936f48 upstream.

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: 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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/boot/compressed/eboot.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- 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_
 		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_
 		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_
 			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_
 		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_
 		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_
 			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,


Patches currently in stable-queue which might be from dirty.ice.hu@gmail.com are

queue-4.2/x86-efi-fix-multiple-gop-device-support.patch