disp: msm: sde: avoid rc lock deadlock during esd failure

Each mode_set call makes sure that previous frame is triggered
and triggers the esd check if there is pp_timeout. This may
lead to deadlock between crtc commit and event threads. Crtc
commit thread acquires the rc_lock and triggers the flush_thread
API on event_thread. Event thread again tries to acquire the
rc_lock to wait for frame. This can be prevented by avoiding the
pre_kickoff call from esd_failure notification if it is generated
through pp_timeout.

Change-Id: I561fef0345976ab0cae61aab6718214c47fa1393
Signed-off-by: Dhaval Patel <[email protected]>

msm/sde/sde_connector.c

@@ -1918,7 +1918,8 @@ static int sde_connector_atomic_check(struct drm_connector *connector,
 	return 0;
 }
 
-static void _sde_connector_report_panel_dead(struct sde_connector *conn)
+static void _sde_connector_report_panel_dead(struct sde_connector *conn,
+	bool skip_pre_kickoff)
 {
 	struct drm_event event;
 
@@ -1938,7 +1939,8 @@ static void _sde_connector_report_panel_dead(struct sde_connector *conn)
 	event.length = sizeof(bool);
 	msm_mode_object_event_notify(&conn->base.base,
 		conn->base.dev, &event, (u8 *)&conn->panel_dead);
-	sde_encoder_display_failure_notification(conn->encoder);
+	sde_encoder_display_failure_notification(conn->encoder,
+		skip_pre_kickoff);
 	SDE_EVT32(SDE_EVTLOG_ERROR);
 	SDE_ERROR("esd check failed report PANEL_DEAD conn_id: %d enc_id: %d\n",
 			conn->base.base.id, conn->encoder->base.id);
@@ -1973,7 +1975,7 @@ int sde_connector_esd_status(struct drm_connector *conn)
 	if (ret <= 0) {
 		/* cancel if any pending esd work */
 		sde_connector_schedule_status_work(conn, false);
-		_sde_connector_report_panel_dead(sde_conn);
+		_sde_connector_report_panel_dead(sde_conn, true);
 		ret = -ETIMEDOUT;
 	} else {
 		SDE_DEBUG("Successfully received TE from panel\n");
@@ -2021,7 +2023,7 @@ static void sde_connector_check_status_work(struct work_struct *work)
 		return;
 	}
 
-	_sde_connector_report_panel_dead(conn);
+	_sde_connector_report_panel_dead(conn, false);
 }
 
 static const struct drm_connector_helper_funcs sde_connector_helper_ops = {

msm/sde/sde_encoder.c

@@ -5813,7 +5813,8 @@ int sde_encoder_update_caps_for_cont_splash(struct drm_encoder *encoder,
 	return ret;
 }
 
-int sde_encoder_display_failure_notification(struct drm_encoder *enc)
+int sde_encoder_display_failure_notification(struct drm_encoder *enc,
+	bool skip_pre_kickoff)
 {
 	struct msm_drm_thread *event_thread = NULL;
 	struct msm_drm_private *priv = NULL;
@@ -5839,9 +5840,11 @@ int sde_encoder_display_failure_notification(struct drm_encoder *enc)
 
 	event_thread = &priv->event_thread[sde_enc->crtc->index];
 
-	kthread_queue_work(&event_thread->worker,
-			   &sde_enc->esd_trigger_work);
-	kthread_flush_work(&sde_enc->esd_trigger_work);
+	if (!skip_pre_kickoff) {
+		kthread_queue_work(&event_thread->worker,
+				   &sde_enc->esd_trigger_work);
+		kthread_flush_work(&sde_enc->esd_trigger_work);
+	}
 
 	/**
 	 * panel may stop generating te signal (vsync) during esd failure. rsc
@@ -5850,7 +5853,8 @@ int sde_encoder_display_failure_notification(struct drm_encoder *enc)
 	 */
 	_sde_encoder_switch_to_watchdog_vsync(enc);
 
-	sde_encoder_wait_for_event(enc, MSM_ENC_TX_COMPLETE);
+	if (!skip_pre_kickoff)
+		sde_encoder_wait_for_event(enc, MSM_ENC_TX_COMPLETE);
 
 	return 0;
 }

msm/sde/sde_encoder.h

@@ -253,9 +253,12 @@ int sde_encoder_update_caps_for_cont_splash(struct drm_encoder *encoder,
  *
  *      TODO: manage the event at sde_kms level for forward processing.
  * @drm_enc:    Pointer to drm encoder structure
+ * @skip_pre_kickoff:    Caller can avoid pre_kickoff if it is triggering this
+ *                       event only to switch the panel TE to watchdog mode.
  * @Return:     true if successful in updating the encoder structure
  */
-int sde_encoder_display_failure_notification(struct drm_encoder *enc);
+int sde_encoder_display_failure_notification(struct drm_encoder *enc,
+	bool skip_pre_kickoff);
 
 /**
  * sde_encoder_recovery_events_enabled - checks if client has enabled