drm/dp_mst: Print errors on ACT timeouts

Although it's not unexpected for drm_dp_check_act_status() to fail due
to DPCD read failures (as the hub may have just been unplugged
suddenly), timeouts are a bit more worrying as they either mean we need
a longer timeout value, or we aren't setting up payload allocations
properly. So, let's start printing errors on timeouts.
Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Sean Paul <sean@poorly.run>
Reviewed-by: Sean Paul <sean@poorly.run>
Link: https://patchwork.freedesktop.org/patch/msgid/20200406221253.1307209-5-lyude@redhat.com

drivers/gpu/drm/drm_dp_mst_topology.c

@@ -4477,10 +4477,14 @@ int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
 				 status & DP_PAYLOAD_ACT_HANDLED || status < 0,
 				 200, timeout_ms * USEC_PER_MSEC);
 	if (ret < 0 && status >= 0) {
-		DRM_DEBUG_KMS("Failed to get ACT after %dms, last status: %02x\n",
-			      timeout_ms, status);
+		DRM_ERROR("Failed to get ACT after %dms, last status: %02x\n",
+			  timeout_ms, status);
 		return -EINVAL;
 	} else if (status < 0) {
+		/*
+		 * Failure here isn't unexpected - the hub may have
+		 * just been unplugged
+		 */
 		DRM_DEBUG_KMS("Failed to read payload table status: %d\n",
 			      status);
 		return status;