gpu: host1x: Remove cancelled waiters immediately

Before this patch, cancelled waiters would only be cleaned up
once their threshold value was reached. Make host1x_intr_put_ref
process the cancellation immediately to fix this.
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/host1x/intr.c

@@ -242,18 +242,29 @@ int host1x_intr_add_action(struct host1x *host, struct host1x_syncpt *syncpt,
 	return 0;
 }
 
-void host1x_intr_put_ref(struct host1x *host, unsigned int id, void *ref)
+void host1x_intr_put_ref(struct host1x *host, unsigned int id, void *ref,
+			 bool flush)
 {
 	struct host1x_waitlist *waiter = ref;
 	struct host1x_syncpt *syncpt;
 
-	while (atomic_cmpxchg(&waiter->state, WLS_PENDING, WLS_CANCELLED) ==
-	       WLS_REMOVED)
-		schedule();
+	atomic_cmpxchg(&waiter->state, WLS_PENDING, WLS_CANCELLED);
 
 	syncpt = host->syncpt + id;
-	(void)process_wait_list(host, syncpt,
-				host1x_syncpt_load(host->syncpt + id));
+
+	spin_lock(&syncpt->intr.lock);
+	if (atomic_cmpxchg(&waiter->state, WLS_CANCELLED, WLS_HANDLED) ==
+	    WLS_CANCELLED) {
+		list_del(&waiter->list);
+		kref_put(&waiter->refcount, waiter_release);
+	}
+	spin_unlock(&syncpt->intr.lock);
+
+	if (flush) {
+		/* Wait until any concurrently executing handler has finished. */
+		while (atomic_read(&waiter->state) != WLS_HANDLED)
+			schedule();
+	}
 
 	kref_put(&waiter->refcount, waiter_release);
 }

drivers/gpu/host1x/intr.h

@@ -74,8 +74,10 @@ int host1x_intr_add_action(struct host1x *host, struct host1x_syncpt *syncpt,
  * Unreference an action submitted to host1x_intr_add_action().
  * You must call this if you passed non-NULL as ref.
  * @ref the ref returned from host1x_intr_add_action()
+ * @flush wait until any pending handlers have completed before returning.
  */
-void host1x_intr_put_ref(struct host1x *host, unsigned int id, void *ref);
+void host1x_intr_put_ref(struct host1x *host, unsigned int id, void *ref,
+			 bool flush);
 
 /* Initialize host1x sync point interrupt */
 int host1x_intr_init(struct host1x *host, unsigned int irq_sync);

drivers/gpu/host1x/syncpt.c

@@ -308,7 +308,7 @@ int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
 		}
 	}
 
-	host1x_intr_put_ref(sp->host, sp->id, ref);
+	host1x_intr_put_ref(sp->host, sp->id, ref, true);
 
 done:
 	return err;