disp: msm: sde: use different spin lock for frame events

Due to lock sequence inconsistency between sde_crtc->spin_lock and
sde_kms->hw_intr->irq_lock can cause deadlock, to avoid this possible
deadlock this change uses different spin lock for frame events.

Change-Id: I51b1184dfa1069c87653099b95b992b277721daf
Signed-off-by: Narendra Muppalla <[email protected]>

msm/sde/sde_crtc.c

@@ -2328,12 +2328,12 @@ static void sde_crtc_frame_event_cb(void *data, u32 event, ktime_t ts)
 	SDE_DEBUG("crtc%d\n", crtc->base.id);
 	SDE_EVT32_VERBOSE(DRMID(crtc), event);
 
-	spin_lock_irqsave(&sde_crtc->spin_lock, flags);
+	spin_lock_irqsave(&sde_crtc->fevent_spin_lock, flags);
 	fevent = list_first_entry_or_null(&sde_crtc->frame_event_list,
 			struct sde_crtc_frame_event, list);
 	if (fevent)
 		list_del_init(&fevent->list);
-	spin_unlock_irqrestore(&sde_crtc->spin_lock, flags);
+	spin_unlock_irqrestore(&sde_crtc->fevent_spin_lock, flags);
 
 	if (!fevent) {
 		SDE_ERROR("crtc%d event %d overflow\n",
@@ -2633,9 +2633,9 @@ static void sde_crtc_frame_event_work(struct kthread_work *work)
 		SDE_ERROR("crtc%d ts:%lld received panel dead event\n",
 				crtc->base.id, ktime_to_ns(fevent->ts));
 
-	spin_lock_irqsave(&sde_crtc->spin_lock, flags);
+	spin_lock_irqsave(&sde_crtc->fevent_spin_lock, flags);
 	list_add_tail(&fevent->list, &sde_crtc->frame_event_list);
-	spin_unlock_irqrestore(&sde_crtc->spin_lock, flags);
+	spin_unlock_irqrestore(&sde_crtc->fevent_spin_lock, flags);
 	SDE_ATRACE_END("crtc_frame_event");
 }
 
@@ -6947,6 +6947,7 @@ struct drm_crtc *sde_crtc_init(struct drm_device *dev, struct drm_plane *plane)
 
 	mutex_init(&sde_crtc->crtc_lock);
 	spin_lock_init(&sde_crtc->spin_lock);
+	spin_lock_init(&sde_crtc->fevent_spin_lock);
 	atomic_set(&sde_crtc->frame_pending, 0);
 
 	sde_crtc->enabled = false;

msm/sde/sde_crtc.h

@@ -263,7 +263,8 @@ struct sde_crtc_misr_info {
  * @frame_pending : Whether or not an update is pending
  * @frame_events  : static allocation of in-flight frame events
  * @frame_event_list : available frame event list
- * @spin_lock     : spin lock for frame event, transaction status, etc...
+ * @spin_lock     : spin lock for transaction status, etc...
+ * @fevent_spin_lock     : spin lock for frame event
  * @event_thread  : Pointer to event handler thread
  * @event_worker  : Event worker queue
  * @event_cache   : Local cache of event worker structures
@@ -350,6 +351,7 @@ struct sde_crtc {
 	struct sde_crtc_frame_event frame_events[SDE_CRTC_FRAME_EVENT_SIZE];
 	struct list_head frame_event_list;
 	spinlock_t spin_lock;
+	spinlock_t fevent_spin_lock;
 
 	/* for handling internal event thread */
 	struct sde_crtc_event event_cache[SDE_CRTC_MAX_EVENT_COUNT];