drm/amd/display: Fix programming backlight on OLED panels

commit 38077562e059 ("drm/amd/display: Implement new
backlight_level_params structure") adjusted DC core to require
the backlight type to be programmed in the dc link when changing
brightness.  This isn't initialized in amdgpu_dm for OLED panels
though which broke brightness.

Explicitly initialize when aux support is enabled.

Reported-and-tested-by: Luke Jones <luke@ljones.dev>
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3792
Fixes: 38077562e059 ("drm/amd/display: Implement new backlight_level_params structure")
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Link: https://lore.kernel.org/r/20241128032200.2085398-1-superm1@kernel.org
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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 f0a6816709ca7dad6415d16f9806f18065026cf7..48be917e7bc550065acb383cd239c9d5c2ea7d83 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -3481,6 +3481,8 @@ static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector)
                caps->aux_support = false;
        else if (amdgpu_backlight == 1)
                caps->aux_support = true;
+       if (caps->aux_support)
+               aconnector->dc_link->backlight_control_type = BACKLIGHT_CONTROL_AMD_AUX;
 
        luminance_range = &conn_base->display_info.luminance_range;