Commit a4d32303 authored by Hamza Mahfooz's avatar Hamza Mahfooz Committed by Alex Deucher
Browse files

drm/amd/display: implement DSC pass-through support 



Currently, we only attempt to setup DSC at the virtual DPCD port,
however many modern displays come with DSC support and MST hubs can now
support DSC pass-through. So, to more optimally make use of the
available bandwidth, use DSC pass-through when possible by adding DSC
pass-through enablement support into the DSC enable sequence.

Signed-off-by: default avatarHamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 8350bb59

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

+41 −4
Original line number Diff line number Diff line
@@ -729,8 +729,14 @@ bool dm_helpers_dp_write_dsc_enable( 
		const struct dc_stream_state *stream,

		bool enable)

{

	uint8_t enable_dsc = enable ? 1 : 0;

	static const uint8_t DSC_DISABLE;

	static const uint8_t DSC_DECODING = 0x01;

	static const uint8_t DSC_PASSTHROUGH = 0x02;



	struct amdgpu_dm_connector *aconnector;

	struct drm_dp_mst_port *port;

	uint8_t enable_dsc = enable ? DSC_DECODING : DSC_DISABLE;

	uint8_t enable_passthrough = enable ? DSC_PASSTHROUGH : DSC_DISABLE;

	uint8_t ret = 0;



	if (!stream)
@@ -750,8 +756,39 @@ bool dm_helpers_dp_write_dsc_enable( 
				aconnector->dsc_aux, stream, enable_dsc);

#endif



		ret = drm_dp_dpcd_write(aconnector->dsc_aux, DP_DSC_ENABLE, &enable_dsc, 1);

		DC_LOG_DC("Send DSC %s to MST RX\n", enable_dsc ? "enable" : "disable");

		port = aconnector->port;



		if (enable) {

			if (port->passthrough_aux) {

				ret = drm_dp_dpcd_write(port->passthrough_aux,

							DP_DSC_ENABLE,

							&enable_passthrough, 1);

				DC_LOG_DC("Sent DSC pass-through enable to virtual dpcd port, ret = %u\n",

					  ret);

			}



			ret = drm_dp_dpcd_write(aconnector->dsc_aux,

						DP_DSC_ENABLE, &enable_dsc, 1);

			DC_LOG_DC("Sent DSC decoding enable to %s port, ret = %u\n",

				  (port->passthrough_aux) ? "remote RX" :

				  "virtual dpcd",

				  ret);

		} else {

			ret = drm_dp_dpcd_write(aconnector->dsc_aux,

						DP_DSC_ENABLE, &enable_dsc, 1);

			DC_LOG_DC("Sent DSC decoding disable to %s port, ret = %u\n",

				  (port->passthrough_aux) ? "remote RX" :

				  "virtual dpcd",

				  ret);



			if (port->passthrough_aux) {

				ret = drm_dp_dpcd_write(port->passthrough_aux,

							DP_DSC_ENABLE,

							&enable_passthrough, 1);

				DC_LOG_DC("Sent DSC pass-through disable to virtual dpcd port, ret = %u\n",

					  ret);

			}

		}

	}



	if (stream->signal == SIGNAL_TYPE_DISPLAY_PORT || stream->signal == SIGNAL_TYPE_EDP) {
@@ -768,7 +805,7 @@ bool dm_helpers_dp_write_dsc_enable( 
#endif

	}



	return (ret > 0);

	return ret;

}



bool dm_helpers_is_dp_sink_present(struct dc_link *link)