From: Mario Limonciello Date: Sun, 23 Feb 2025 05:37:32 +0000 (-0600) Subject: drm/amd/display: fix default brightness X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=0747acf3311229e22009bec4a9e7fc30c879e842;p=users%2Fhch%2Fmisc.git drm/amd/display: fix default brightness [Why] To avoid flickering during boot default brightness level set by BIOS should be maintained for as much of the boot as feasible. commit 2fe87f54abdc ("drm/amd/display: Set default brightness according to ACPI") attempted to set the right levels for AC vs DC, but brightness still got reset to maximum level in initialization code for setup_backlight_device(). [How] Remove the hardcoded initialization in setup_backlight_device() and instead program brightness value to match BIOS (AC or DC). This avoids a brightness flicker from kernel changing the value. Userspace may however still change it during boot. Fixes: 2fe87f54abdc ("drm/amd/display: Set default brightness according to ACPI") Acked-by: Wayne Lin Signed-off-by: Mario Limonciello Signed-off-by: Tom Chung Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher --- diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 6a54f1cfa125..5ae521d1b74b 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -4986,6 +4986,7 @@ amdgpu_dm_register_backlight_device(struct amdgpu_dm_connector *aconnector) dm->backlight_dev[aconnector->bl_idx] = backlight_device_register(bl_name, aconnector->base.kdev, dm, &amdgpu_dm_backlight_ops, &props); + dm->brightness[aconnector->bl_idx] = props.brightness; if (IS_ERR(dm->backlight_dev[aconnector->bl_idx])) { DRM_ERROR("DM: Backlight registration failed!\n"); @@ -5053,7 +5054,6 @@ static void setup_backlight_device(struct amdgpu_display_manager *dm, aconnector->bl_idx = bl_idx; amdgpu_dm_update_backlight_caps(dm, bl_idx); - dm->brightness[bl_idx] = AMDGPU_MAX_BL_LEVEL; dm->backlight_link[bl_idx] = link; dm->num_of_edps++;