drm/radeon/dp: Probe branch/sink OUIs

Signed-off-by: Adam Jackson <ajax@redhat.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c
index cadbb10..5131b3b 100644
--- a/drivers/gpu/drm/radeon/atombios_dp.c
+++ b/drivers/gpu/drm/radeon/atombios_dp.c
@@ -530,6 +530,23 @@
 					 dig_connector->dp_i2c_bus->rec.i2c_id, 0);
 }
 
+static void radeon_dp_probe_oui(struct radeon_connector *radeon_connector)
+{
+	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
+	u8 buf[3];
+
+	if (!(dig_connector->dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
+		return;
+
+	if (radeon_dp_aux_native_read(radeon_connector, DP_SINK_OUI, buf, 3, 0))
+		DRM_DEBUG_KMS("Sink OUI: %02hx%02hx%02hx\n",
+			      buf[0], buf[1], buf[2]);
+
+	if (radeon_dp_aux_native_read(radeon_connector, DP_BRANCH_OUI, buf, 3, 0))
+		DRM_DEBUG_KMS("Branch OUI: %02hx%02hx%02hx\n",
+			      buf[0], buf[1], buf[2]);
+}
+
 bool radeon_dp_getdpcd(struct radeon_connector *radeon_connector)
 {
 	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
@@ -543,6 +560,9 @@
 		for (i = 0; i < 8; i++)
 			DRM_DEBUG_KMS("%02x ", msg[i]);
 		DRM_DEBUG_KMS("\n");
+
+		radeon_dp_probe_oui(radeon_connector);
+
 		return true;
 	}
 	dig_connector->dpcd[0] = 0;