drm/msm/atomic: Convert to per-CRTC kthread_work

Use a SCHED_FIFO kthread_worker for async atomic commits.  We have a
hard deadline if we don't want to miss a frame.

Signed-off-by: Rob Clark <robdclark@chromium.org>

1 files changed, 20 insertions, 5 deletions

diff --git a/drivers/gpu/drm/msm/msm_atomic.c b/drivers/gpu/drm/msm/msm_atomic.c
index 93d39608a073..6a326761dc4a 100644
--- a/drivers/gpu/drm/msm/msm_atomic.c
+++ b/drivers/gpu/drm/msm/msm_atomic.c
@@ -117,14 +117,13 @@ static enum hrtimer_restart msm_atomic_pending_timer(struct hrtimer *t)
 {
 	struct msm_pending_timer *timer = container_of(t,
 			struct msm_pending_timer, timer);
-	struct msm_drm_private *priv = timer->kms->dev->dev_private;
 
-	queue_work(priv->wq, &timer->work);
+	kthread_queue_work(timer->worker, &timer->work);
 
 	return HRTIMER_NORESTART;
 }
 
-static void msm_atomic_pending_work(struct work_struct *work)
+static void msm_atomic_pending_work(struct kthread_work *work)
 {
 	struct msm_pending_timer *timer = container_of(work,
 			struct msm_pending_timer, work);
@@ -132,14 +131,30 @@ static void msm_atomic_pending_work(struct work_struct *work)
 	msm_atomic_async_commit(timer->kms, timer->crtc_idx);
 }
 
-void msm_atomic_init_pending_timer(struct msm_pending_timer *timer,
+int msm_atomic_init_pending_timer(struct msm_pending_timer *timer,
 		struct msm_kms *kms, int crtc_idx)
 {
 	timer->kms = kms;
 	timer->crtc_idx = crtc_idx;
 	hrtimer_init(&timer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
 	timer->timer.function = msm_atomic_pending_timer;
-	INIT_WORK(&timer->work, msm_atomic_pending_work);
+
+	timer->worker = kthread_create_worker(0, "atomic-worker-%d", crtc_idx);
+	if (IS_ERR(timer->worker)) {
+		int ret = PTR_ERR(timer->worker);
+		timer->worker = NULL;
+		return ret;
+	}
+	sched_set_fifo(timer->worker->task);
+	kthread_init_work(&timer->work, msm_atomic_pending_work);
+
+	return 0;
+}
+
+void msm_atomic_destroy_pending_timer(struct msm_pending_timer *timer)
+{
+	if (timer->worker)
+		kthread_destroy_worker(timer->worker);
 }
 
 static bool can_do_async(struct drm_atomic_state *state,