Commit 4fd17f2a authored by Roman Li's avatar Roman Li Committed by Alex Deucher
Browse files

drm/amd/display: Cap OLED brightness per max frame-average luminance 



[Why]
For OLED eDP the Display Manager uses max_cll value as a limit
for brightness control.
max_cll defines the content light luminance for individual pixel.
Whereas max_fall defines frame-average level luminance.
The user may not observe the difference in brightness in between
max_fall and max_cll.
That negatively impacts the user experience.

[How]
Use max_fall value instead of max_cll as a limit for brightness control.

Reviewed-by: default avatarRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Acked-by: default avatarHamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: default avatarRoman Li <roman.li@amd.com>
Tested-by: default avatarDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
parent c904e3ac

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

+4 −4
Original line number Diff line number Diff line
@@ -2812,7 +2812,7 @@ static struct drm_mode_config_helper_funcs amdgpu_dm_mode_config_helperfuncs = { 


static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector)

{

	u32 max_cll, min_cll, max, min, q, r;

	u32 max_avg, min_cll, max, min, q, r;

	struct amdgpu_dm_backlight_caps *caps;

	struct amdgpu_display_manager *dm;

	struct drm_connector *conn_base;
@@ -2842,7 +2842,7 @@ static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector) 
	caps = &dm->backlight_caps[i];

	caps->ext_caps = &aconnector->dc_link->dpcd_sink_ext_caps;

	caps->aux_support = false;

	max_cll = conn_base->hdr_sink_metadata.hdmi_type1.max_cll;

	max_avg = conn_base->hdr_sink_metadata.hdmi_type1.max_fall;

	min_cll = conn_base->hdr_sink_metadata.hdmi_type1.min_cll;



	if (caps->ext_caps->bits.oled == 1 /*||
@@ -2870,8 +2870,8 @@ static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector) 
	 * The results of the above expressions can be verified at

	 * pre_computed_values.

	 */

	q = max_cll >> 5;

	r = max_cll % 32;

	q = max_avg >> 5;

	r = max_avg % 32;

	max = (1 << q) * pre_computed_values[r];



	// min luminance: maxLum * (CV/255)^2 / 100