drm/amd/display: cache additional dpcd caps for HDR capability check

[Why]
Currently we are missing a few checks to see if HDR10 is allowed.
In particular we never check for the extended colorimetry bit (whether its
present or set to 1). Further we don't read in the dpcd block in DC that
would provide these bits.

[How]
- Added in DC code to read in the block containing the extended colorimetry
bit.

Signed-off-by: Harmanprit Tatla <Harmanprit.Tatla@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 33 insertions, 4 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
index e1081e2dffdc..ef603f24c71c 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
@@ -2418,6 +2418,10 @@ static bool retrieve_link_cap(struct dc_link *link)
 {
 	uint8_t dpcd_data[DP_ADAPTER_CAP - DP_DPCD_REV + 1];
 
+	/*Only need to read 1 byte starting from DP_DPRX_FEATURE_ENUMERATION_LIST.
+	 */
+	uint8_t dpcd_dprx_data = '\0';
+
 	struct dp_device_vendor_id sink_id;
 	union down_stream_port_count down_strm_port_count;
 	union edp_configuration_cap edp_config_cap;
@@ -2454,7 +2458,10 @@ static bool retrieve_link_cap(struct dc_link *link)
 		aux_rd_interval.raw =
 			dpcd_data[DP_TRAINING_AUX_RD_INTERVAL];
 
-		if (aux_rd_interval.bits.EXT_RECIEVER_CAP_FIELD_PRESENT == 1) {
+		link->dpcd_caps.ext_receiver_cap_field_present =
+				aux_rd_interval.bits.EXT_RECEIVER_CAP_FIELD_PRESENT == 1 ? true:false;
+
+		if (aux_rd_interval.bits.EXT_RECEIVER_CAP_FIELD_PRESENT == 1) {
 			uint8_t ext_cap_data[16];
 
 			memset(ext_cap_data, '\0', sizeof(ext_cap_data));
@@ -2474,6 +2481,31 @@ static bool retrieve_link_cap(struct dc_link *link)
 		}
 	}
 
+	link->dpcd_caps.dpcd_rev.raw =
+			dpcd_data[DP_DPCD_REV - DP_DPCD_REV];
+
+	if (link->dpcd_caps.dpcd_rev.raw >= 0x14) {
+		for (i = 0; i < read_dpcd_retry_cnt; i++) {
+			status = core_link_read_dpcd(
+					link,
+					DP_DPRX_FEATURE_ENUMERATION_LIST,
+					&dpcd_dprx_data,
+					sizeof(dpcd_dprx_data));
+			if (status == DC_OK)
+				break;
+		}
+
+		link->dpcd_caps.dprx_feature.raw = dpcd_dprx_data;
+
+		if (status != DC_OK)
+			dm_error("%s: Read DPRX caps data failed.\n", __func__);
+	}
+
+	else {
+		link->dpcd_caps.dprx_feature.raw = 0;
+	}
+
+
 	/* Error condition checking...
 	 * It is impossible for Sink to report Max Lane Count = 0.
 	 * It is possible for Sink to report Max Link Rate = 0, if it is
@@ -2483,9 +2515,6 @@ static bool retrieve_link_cap(struct dc_link *link)
 	if (dpcd_data[DP_MAX_LANE_COUNT - DP_DPCD_REV] == 0)
 		return false;
 
-	link->dpcd_caps.dpcd_rev.raw =
-		dpcd_data[DP_DPCD_REV - DP_DPCD_REV];
-
 	ds_port.byte = dpcd_data[DP_DOWNSTREAMPORT_PRESENT -
 				 DP_DPCD_REV];