efifb: Skip DMI checks if the bootloader knows what it's doing (f462ed93) · Commits · 戴 / test

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 <mjg@redhat.com> Acked-by:

Peter Jones <pjones@redhat.com> Signed-off-by:

Matt Fleming <matt.fleming@intel.com>

arch/x86/boot/compressed/eboot.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -379,6 +379,8 @@ 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;

drivers/video/efifb.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -553,6 +553,8 @@ static int __init efifb_init(void)
		int ret;
		char *option = NULL;

		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)

include/linux/screen_info.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -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;

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