drm/amd/display: Write TEST_EDID_CHECKSUM_WRITE for EDID tests

Extract edid's checksum and send it back for verification if EDID_TEST
is requested.

Also added a flag for EDID checksum write in TEST_RESPONSE structure,
and simple spelling fix.

Signed-off-by: Mikita Lipski <mikita.lipski@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -497,6 +497,34 @@ enum dc_edid_status dm_helpers_read_local_edid(
 		DRM_ERROR("EDID err: %d, on connector: %s",
 				edid_status,
 				aconnector->base.name);
+	if (link->aux_mode) {
+		union test_request test_request = {0};
+		union test_response test_response = {0};
+
+		dm_helpers_dp_read_dpcd(ctx,
+					link,
+					DP_TEST_REQUEST,
+					&test_request.raw,
+					sizeof(union test_request));
+
+		if (!test_request.bits.EDID_READ)
+			return edid_status;
+
+		test_response.bits.EDID_CHECKSUM_WRITE = 1;
+
+		dm_helpers_dp_write_dpcd(ctx,
+					link,
+					DP_TEST_EDID_CHECKSUM,
+					&sink->dc_edid.raw_edid[sink->dc_edid.length-1],
+					1);
+
+		dm_helpers_dp_write_dpcd(ctx,
+					link,
+					DP_TEST_RESPONSE,
+					&test_response.raw,
+					sizeof(test_response));
+
+	}
 
 	return edid_status;
 }

drivers/gpu/drm/amd/display/dc/dc_dp_types.h

@@ -430,7 +430,7 @@ union test_request {
 	struct {
 	uint8_t LINK_TRAINING         :1;
 	uint8_t LINK_TEST_PATTRN      :1;
-	uint8_t EDID_REAT             :1;
+	uint8_t EDID_READ             :1;
 	uint8_t PHY_TEST_PATTERN      :1;
 	uint8_t AUDIO_TEST_PATTERN    :1;
 	uint8_t RESERVED              :1;
@@ -443,7 +443,8 @@ union test_response {
 	struct {
 		uint8_t ACK         :1;
 		uint8_t NO_ACK      :1;
-		uint8_t RESERVED    :6;
+		uint8_t EDID_CHECKSUM_WRITE:1;
+		uint8_t RESERVED    :5;
 	} bits;
 	uint8_t raw;
 };