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>

diff --git a/drivers/gpu/drm/msm/msm_atomic.c b/drivers/gpu/drm/msm/msm_atomic.c
index 93d3960..6a32676 100644 (file)
--- 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,

diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
index b9dd8f8..1a37712 100644 (file)
--- a/drivers/gpu/drm/msm/msm_drv.h
+++ b/drivers/gpu/drm/msm/msm_drv.h
@@ -228,8 +228,9 @@ struct msm_pending_timer;
 
 int msm_atomic_prepare_fb(struct drm_plane *plane,
                          struct drm_plane_state *new_state);
-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);
+void msm_atomic_destroy_pending_timer(struct msm_pending_timer *timer);
 void msm_atomic_commit_tail(struct drm_atomic_state *state);
 struct drm_atomic_state *msm_atomic_state_alloc(struct drm_device *dev);
 void msm_atomic_state_clear(struct drm_atomic_state *state);

diff --git a/drivers/gpu/drm/msm/msm_kms.h b/drivers/gpu/drm/msm/msm_kms.h
index 602c0c7..d8151a8 100644 (file)
--- a/drivers/gpu/drm/msm/msm_kms.h
+++ b/drivers/gpu/drm/msm/msm_kms.h
@@ -136,7 +136,8 @@ struct msm_kms;
  */
 struct msm_pending_timer {
        struct hrtimer timer;
-       struct work_struct work;
+       struct kthread_work work;
+       struct kthread_worker *worker;
        struct msm_kms *kms;
        unsigned crtc_idx;
 };
@@ -163,21 +164,29 @@ struct msm_kms {
 static inline int msm_kms_init(struct msm_kms *kms,
                const struct msm_kms_funcs *funcs)
 {
-       unsigned i;
+       unsigned i, ret;
 
        for (i = 0; i < ARRAY_SIZE(kms->commit_lock); i++)
                mutex_init(&kms->commit_lock[i]);
 
        kms->funcs = funcs;
 
-       for (i = 0; i < ARRAY_SIZE(kms->pending_timers); i++)
-               msm_atomic_init_pending_timer(&kms->pending_timers[i], kms, i);
+       for (i = 0; i < ARRAY_SIZE(kms->pending_timers); i++) {
+               ret = msm_atomic_init_pending_timer(&kms->pending_timers[i], kms, i);
+               if (ret) {
+                       return ret;
+               }
+       }
 
        return 0;
 }
 
 static inline void msm_kms_destroy(struct msm_kms *kms)
 {
+       unsigned i;
+
+       for (i = 0; i < ARRAY_SIZE(kms->pending_timers); i++)
+               msm_atomic_destroy_pending_timer(&kms->pending_timers[i]);
 }
 
 struct msm_kms *mdp4_kms_init(struct drm_device *dev);