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 <hamza.mahf...@amd.com>
---
v2: print the correct type of port that we are writing to using dsc_aux
in dm_helpers_dp_write_dsc_enable().
---
.../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 a0154a5f7183..bd364d2cc4f7 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)
--
2.37.1
