From a4d3230353e493d98263c5d7f03ee6403ed82d71 Mon Sep 17 00:00:00 2001 From: Hamza Mahfooz Date: Mon, 18 Jul 2022 16:50:45 -0400 Subject: [PATCH] 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: Hamza Mahfooz Signed-off-by: Alex Deucher --- .../drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 45 ++++++++++++++++++++-- 1 file changed, 41 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c index a0154a5..bd364d2 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c @@ -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) -- 2.7.4