https://bugs.kde.org/show_bug.cgi?id=503268
--- Comment #28 from Ilia Kats <[email protected]> --- I looked at the changelog for kernel 6.16.10, and this looks relevant (I don't have HDR enabled btw): commit 3bf00f58a8075fe881890cb21b753105f231713d Author: Matthew Schwartz <[email protected]> Date: Thu Sep 11 10:48:51 2025 -0700 drm/amd/display: Only restore backlight after amdgpu_dm_init or dm_resume commit 44b0fed0a5947f54fd14255cd0766df952267bc5 upstream. On clients that utilize AMD_PRIVATE_COLOR properties for HDR support, brightness sliders can include a hardware controlled portion and a gamma-based portion. This is the case on the Steam Deck OLED when using gamescope with Steam as a client. When a user sets a brightness level while HDR is active, the gamma-based portion and/or hardware portion are adjusted to achieve the desired brightness. However, when a modeset takes place while the gamma-based portion is in-use, restoring the hardware brightness level overrides the user's overall brightness level and results in a mismatch between what the slider reports and the display's current brightness. To avoid overriding gamma-based brightness, only restore HW backlight level after boot or resume. This ensures that the backlight level is set correctly after the DC layer resets it while avoiding interference with subsequent modesets. Fixes: 7875afafba84 ("drm/amd/display: Fix brightness level not retained over reboot") Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4551 Signed-off-by: Matthew Schwartz <[email protected]> Reviewed-by: Mario Limonciello <[email protected]> Signed-off-by: Mario Limonciello <[email protected]> Signed-off-by: Alex Deucher <[email protected]> (cherry picked from commit a490c8d77d500b5981e739be3d59c60cfe382536) Cc: [email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]> -- You are receiving this mail because: You are watching all bug changes.
