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

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Message-ID: <20251124165116.502813-1-tzimmermann@suse.de>
Date: Mon, 24 Nov 2025 17:40:12 +0100
From: Thomas Zimmermann <tzimmermann@...e.de>
To: ardb@...nel.org,
	javierm@...hat.com,
	arnd@...db.de,
	richard.lyu@...e.com
Cc: x86@...nel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	linux-efi@...r.kernel.org,
	loongarch@...ts.linux.dev,
	linux-riscv@...ts.infradead.org,
	dri-devel@...ts.freedesktop.org,
	linux-hyperv@...r.kernel.org,
	linux-pci@...r.kernel.org,
	linux-fbdev@...r.kernel.org,
	Thomas Zimmermann <tzimmermann@...e.de>
Subject: [PATCH v2 00/10] arch,sysfb,efi: Support EDID on non-x86 EFI systems

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