1 files changed, 48 insertions, 10 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c b/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c
index 8cc852c7..7a707fbd 100644
--- a/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c
@@ -154,8 +154,23 @@ static int gk20a_channel_syncpt_wait_fd(struct gk20a_channel_sync *s, int fd,
 
 static void gk20a_channel_syncpt_update(void *priv, int nr_completed)
 {
-        struct channel_gk20a *ch20a = priv;
-        gk20a_channel_update(ch20a, nr_completed);
+        struct channel_gk20a *ch = priv;
+        struct gk20a *g = ch->g;
+
+        /* need busy for possible channel deletion */
+        if (gk20a_busy(ch->g->dev)) {
+                gk20a_err(dev_from_gk20a(ch->g),
+                                "failed to busy while syncpt update");
+                /* Last gk20a_idle()s are in channel_update, so we shouldn't
+                 * get here. If we do, the channel is badly broken now */
+                return;
+        }
+
+        /* note: channel_get() is in __gk20a_channel_syncpt_incr() */
+        gk20a_channel_update(ch, nr_completed);
+        gk20a_channel_put(ch);
+
+        gk20a_idle(g->dev);
 }
 
 static int __gk20a_channel_syncpt_incr(struct gk20a_channel_sync *s,
@@ -209,14 +224,37 @@ static int __gk20a_channel_syncpt_incr(struct gk20a_channel_sync *s,
         thresh = nvhost_syncpt_incr_max_ext(sp->host1x_pdev, sp->id, 2);
 
         if (register_irq) {
-                err = nvhost_intr_register_notifier(sp->host1x_pdev,
-                                sp->id, thresh,
-                                gk20a_channel_syncpt_update, c);
-
-                /* Adding interrupt action should never fail. A proper error
-                 * handling here would require us to decrement the syncpt max
-                 * back to its original value. */
-                WARN(err, "failed to set submit complete interrupt");
+                err = gk20a_busy(c->g->dev);
+                if (err)
+                        gk20a_err(dev_from_gk20a(c->g),
+                                  "failed to add syncpt interrupt notifier for channel %d",
+                                  c->hw_chid);
+                else {
+                        struct channel_gk20a *referenced = gk20a_channel_get(c);
+
+                        WARN_ON(!referenced);
+                        gk20a_idle(c->g->dev);
+
+                        if (referenced) {
+                                /* note: channel_put() is in
+                                 * gk20a_channel_syncpt_update() */
+
+                                err = nvhost_intr_register_notifier(
+                                        sp->host1x_pdev,
+                                        sp->id, thresh,
+                                        gk20a_channel_syncpt_update, c);
+                                if (err)
+                                        gk20a_channel_put(referenced);
+
+                                /* Adding interrupt action should
+                                 * never fail. A proper error handling
+                                 * here would require us to decrement
+                                 * the syncpt max back to its original
+                                 * value. */
+                                WARN(err,
+                                     "failed to set submit complete interrupt");
+                        }
+                }
         }
 
         *fence = gk20a_fence_from_syncpt(sp->host1x_pdev, sp->id, thresh,