[PATCH v2 00/10] arch,sysfb,efi: Support EDID on non-x86 EFI systems

Thomas Zimmermann
2025-11-24T16:51:26Z

Replace screen_info and edid_info with sysfb_primary_device of type
struct sysfb_display_info. Update all users. Then implement EDID support
in EFI's libstub.

Sysfb DRM drivers currently fetch the global edid_info directly, when
they should get that information together with the screen_info from their
device. Wrapping screen_info and edid_info in sysfb_primary_display and
passing this to drivers enables this.

Replacing both with sysfb_primary_display has been motivate by the EFI
stub. EFI wants to transfer EDID via config table in a single entry.
Using struct sysfb_display_info this will become easily possible. Hence
accept some churn in architecture code for the long-term improvements.

Add a new UUID to transfer sysfb_primary_display via EFI's config table.
Then implement support in the kernel and EFI's libstub.

Patches 1 and 2 reduce the exposure of screen_info in EFI-related code.

Patch 3 adds struct sysfb_display_info.

Patch 4 replaces scren_info with sysfb_primary_display. This results in
several changes throught the kernel, but is really just a refactoring.

Patch 5 updates sysfb to transfer sysfb_primary_display to the related
drivers.

Patch 6 moves edid_info into sysfb_primary_display. This resolves some
drivers' reference to the global edid_info, but also makes the EDID data
available on non-x86 architectures.

Patches 7 and 8 add kernel-side support for EDID transfers on non-x86
EFI systems.

Patches 9 implements EDID support in libstub. Patch 10 cleans up the
config-table allocation to be easier to understand.

This is v2 of the series. It combines v1 of the series at [1] plus
changes from [2] and [3].

[1] https://lore.kernel.org/dri-devel/20251121135624.494768-1-tzimmermann@suse.de/
[2] https://lore.kernel.org/dri-devel/20251015160816.525825-1-tzimmermann@suse.de/
[3] https://lore.kernel.org/linux-efi/20251119123011.1187249-5-ardb+git@google.com/

Thomas Zimmermann (10):
efi: earlycon: Reduce number of references to global screen_info
efi: sysfb_efi: Reduce number of references to global screen_info
sysfb: Add struct sysfb_display_info
sysfb: Replace screen_info with sysfb_primary_display
sysfb: Pass sysfb_primary_display to devices
sysfb: Move edid_info into sysfb_primary_display
efi: Refactor init_primary_display() helpers
efi: Support EDID information
efi: libstub: Transfer EDID to kernel
efi: libstub: Simplify interfaces for primary_display

arch/arm64/kernel/image-vars.h | 2 +-
arch/loongarch/kernel/efi.c | 47 +++++++----
arch/loongarch/kernel/image-vars.h | 2 +-
arch/riscv/kernel/image-vars.h | 2 +-
arch/x86/kernel/kexec-bzimage64.c | 4 +-
arch/x86/kernel/setup.c | 16 ++--
arch/x86/video/video-common.c | 4 +-
drivers/firmware/efi/earlycon.c | 42 +++++-----
drivers/firmware/efi/efi-init.c | 47 +++++++----
drivers/firmware/efi/efi.c | 2 +
drivers/firmware/efi/libstub/Makefile | 2 +-
drivers/firmware/efi/libstub/efi-stub-entry.c | 36 +++++++--
drivers/firmware/efi/libstub/efi-stub.c | 49 +++++++----
drivers/firmware/efi/libstub/efistub.h | 7 +-
.../firmware/efi/libstub/primary_display.c | 41 ++++++++++
drivers/firmware/efi/libstub/screen_info.c | 53 ------------
drivers/firmware/efi/libstub/zboot.c | 6 +-
drivers/firmware/efi/sysfb_efi.c | 81 ++++++++++---------
drivers/firmware/sysfb.c | 13 +--
drivers/firmware/sysfb_simplefb.c | 2 +-
drivers/gpu/drm/sysfb/efidrm.c | 14 ++--
drivers/gpu/drm/sysfb/vesadrm.c | 14 ++--
drivers/hv/vmbus_drv.c | 6 +-
drivers/pci/vgaarb.c | 4 +-
drivers/video/Kconfig | 8 +-
drivers/video/fbdev/core/fbmon.c | 8 +-
drivers/video/fbdev/efifb.c | 10 ++-
drivers/video/fbdev/vesafb.c | 10 ++-
drivers/video/fbdev/vga16fb.c | 8 +-
drivers/video/screen_info_pci.c | 5 +-
include/linux/efi.h | 8 +-
include/linux/screen_info.h | 2 -
include/linux/sysfb.h | 23 ++++--
include/video/edid.h | 4 -
34 files changed, 337 insertions(+), 245 deletions(-)
create mode 100644 drivers/firmware/efi/libstub/primary_display.c
delete mode 100644 drivers/firmware/efi/libstub/screen_info.c

base-commit: d724c6f85e80a23ed46b7ebc6e38b527c09d64f5
--
2.51.1