From 540f4c0e894f7e46a66dfa424b16424cbdc12c38 Mon Sep 17 00:00:00 2001 From: "Cohen, Eugene" Date: Tue, 4 Apr 2017 16:27:43 +0100 Subject: efi/libstub: Skip GOP with PIXEL_BLT_ONLY format The UEFI Specification permits Graphics Output Protocol (GOP) instances without direct framebuffer access. This is indicated in the Mode structure with a PixelFormat enumeration value of PIXEL_BLT_ONLY. Given that the kernel does not know how to drive a Blt() only framebuffer (which is only permitted before ExitBootServices() anyway), we should disregard such framebuffers when looking for a GOP instance that is suitable for use as the boot console. So modify the EFI GOP initialization to not use a PIXEL_BLT_ONLY instance, preventing attempts later in boot to use an invalid screen_info.lfb_base address. Signed-off-by: Eugene Cohen [ Moved the Blt() only check into the loop and clarified that Blt() only GOPs are unusable by the kernel. ] Signed-off-by: Ard Biesheuvel Cc: # v4.7+ Cc: Linus Torvalds Cc: Matt Fleming Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: leif.lindholm@linaro.org Cc: linux-efi@vger.kernel.org Cc: lorenzo.pieralisi@arm.com Fixes: 9822504c1fa5 ("efifb: Enable the efi-framebuffer platform driver ...") Link: http://lkml.kernel.org/r/20170404152744.26687-2-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar --- drivers/firmware/efi/libstub/gop.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efi/libstub/gop.c b/drivers/firmware/efi/libstub/gop.c index 932742e4cf23..24c461dea7af 100644 --- a/drivers/firmware/efi/libstub/gop.c +++ b/drivers/firmware/efi/libstub/gop.c @@ -149,7 +149,8 @@ setup_gop32(efi_system_table_t *sys_table_arg, struct screen_info *si, status = __gop_query32(sys_table_arg, gop32, &info, &size, ¤t_fb_base); - if (status == EFI_SUCCESS && (!first_gop || conout_found)) { + if (status == EFI_SUCCESS && (!first_gop || conout_found) && + info->pixel_format != PIXEL_BLT_ONLY) { /* * Systems that use the UEFI Console Splitter may * provide multiple GOP devices, not all of which are @@ -266,7 +267,8 @@ setup_gop64(efi_system_table_t *sys_table_arg, struct screen_info *si, status = __gop_query64(sys_table_arg, gop64, &info, &size, ¤t_fb_base); - if (status == EFI_SUCCESS && (!first_gop || conout_found)) { + if (status == EFI_SUCCESS && (!first_gop || conout_found) && + info->pixel_format != PIXEL_BLT_ONLY) { /* * Systems that use the UEFI Console Splitter may * provide multiple GOP devices, not all of which are -- cgit