The value of "min_input_signal" returned from ATIF on a Framework AMD 13 is "12". This leads to a fairly bright minimum display backlight. Add a generic override helper for the user to override the settings provided by the firmware through the kernel cmdline. Also add amdgpu as a user of that helper. One solution would be a fixed firmware version, which was announced but has no timeline. This helper does conflict with the mode override via the cmdline. Only one can be specified. IMO the mode override can be extended to also handle "min-brightness" when that becomes necessary. --- Changes in v3: - Switch to cmdline override parameter - Link to v2: https://lore.kernel.org/r/20240623-amdgpu-min-backlight-quirk-v2-0-cecf7f49da9b@xxxxxxxxxxxxxx Changes in v2: - Introduce proper drm backlight quirk infrastructure - Quirk by EDID and DMI instead of only DMI - Limit quirk to only single Framework 13 matte panel - Link to v1: https://lore.kernel.org/r/20240610-amdgpu-min-backlight-quirk-v1-1-8459895a5b2a@xxxxxxxxxxxxxx --- Thomas Weißschuh (2): drm/connector: add drm_connector_get_cmdline_min_brightness_override() drm/amd/display: implement minimum brightness override drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 6 ++++ drivers/gpu/drm/drm_connector.c | 34 +++++++++++++++++++++++ include/drm/drm_connector.h | 2 ++ 3 files changed, 42 insertions(+) --- base-commit: 36821612eb3091a21f7f4a907b497064725080c3 change-id: 20240610-amdgpu-min-backlight-quirk-8402fd8e736a Best regards, -- Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
