From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752184Ab2G0RDJ (ORCPT ); Fri, 27 Jul 2012 13:03:09 -0400 Received: from mx1.redhat.com ([209.132.183.28]:8514 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751030Ab2G0RDI (ORCPT ); Fri, 27 Jul 2012 13:03:08 -0400 From: Matthew Garrett To: matt.fleming@intel.com Cc: linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, pjones@redhat.com, Matthew Garrett Subject: [PATCH] efifb: Skip DMI checks if the bootloader knows what it's doing Date: Fri, 27 Jul 2012 12:58:53 -0400 Message-Id: <1343408333-665-1-git-send-email-mjg@redhat.com> X-SA-Do-Not-Run: Yes X-SA-Exim-Connect-IP: 209.6.41.104 X-SA-Exim-Mail-From: mjg@redhat.com X-SA-Exim-Scanned: No (on cavan.codon.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The majority of the DMI checks in efifb are for cases where the bootloader has provided invalid information. However, on some machines the overrides may do more harm than good due to configuration differences between machines with the same machine identifier. It turns out that it's possible for the bootloader to get the correct information on GOP-based systems, but we can't guarantee that the kernel's being booted with one that's been updated to do so. Add support for a capabilities flag that can be set by the bootloader, and skip the DMI checks in that case. Additionally, set this flag in the UEFI stub code. Signed-off-by: Matthew Garrett --- arch/x86/boot/compressed/eboot.c | 2 ++ drivers/video/efifb.c | 4 +++- include/linux/screen_info.h | 2 ++ 3 files changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c index b71c7c8..b329312 100644 --- a/arch/x86/boot/compressed/eboot.c +++ b/arch/x86/boot/compressed/eboot.c @@ -495,6 +495,8 @@ static efi_status_t setup_gop(struct screen_info *si, efi_guid_t *proto, si->rsvd_pos = 0; } + si->capabilities |= VIDEO_CAPABILITY_SKIP_QUIRKS; + free_handle: efi_call_phys1(sys_table->boottime->free_pool, gop_handle); return status; diff --git a/drivers/video/efifb.c b/drivers/video/efifb.c index b4a632a..932abaa 100644 --- a/drivers/video/efifb.c +++ b/drivers/video/efifb.c @@ -553,7 +553,9 @@ static int __init efifb_init(void) int ret; char *option = NULL; - dmi_check_system(dmi_system_table); + if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI || + !(screen_info.capabilities & VIDEO_CAPABILITY_SKIP_QUIRKS)) + dmi_check_system(dmi_system_table); if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI) return -ENODEV; diff --git a/include/linux/screen_info.h b/include/linux/screen_info.h index 899fbb4..fb3c5a8 100644 --- a/include/linux/screen_info.h +++ b/include/linux/screen_info.h @@ -68,6 +68,8 @@ struct screen_info { #define VIDEO_FLAGS_NOCURSOR (1 << 0) /* The video mode has no cursor set */ +#define VIDEO_CAPABILITY_SKIP_QUIRKS (1 << 0) + #ifdef __KERNEL__ extern struct screen_info screen_info; -- 1.7.10.4