efi: sysfb_efi: Fix efidrmfb and simpledrmfb on Valve Steam Deck

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Valve Steam Deck has a 800x1280 portrait screen installed in a landscape
orientation. The firmware offers a software-rotated 1280x800 mode, which
GRUB can be made to switch to when displaying a boot menu. If this mode
was selected frame buffer drivers will see this fake mode and fbcon
rendering will be corrupted.

Let us therefore add a selective quirk inside the current "swap with and
height" handling, which will detect this exact mode and fix it up back to
the native one.

This will allow the DRM-based framebuffer drivers to detect the correct
mode, apply the existing panel orientation quirk, and render the console
in landscape mode with no corruption.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Melissa Wen <mwen@igalia.com>
Cc: linux-efi@vger.kernel.org
Tested-by: Melissa Wen <mwen@igalia.com> # v3
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
[ardb: use local var to refer to screen_info]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

...

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Tvrtko Ursulin 2025-12-08 20:39:25 +01:00 • committed by Ard Biesheuvel

parent 7f2f1fd6fc

commit c7c7eb5ed5

1 changed files with 47 additions and 0 deletions

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drivers/firmware/efi/sysfb_efi.c

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