drm/radeon: add error handling to fence_wait_empty_locked

Instead of returning the error handle it directly
and while at it fix the comments about the ring lock.

Signed-off-by: Christian König <deathsimple@vodafone.de>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

2 files changed, 22 insertions, 13 deletions

diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 77b4519b19b8..5861ec86725f 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -239,7 +239,7 @@ void radeon_fence_process(struct radeon_device *rdev, int ring);
 bool radeon_fence_signaled(struct radeon_fence *fence);
 int radeon_fence_wait(struct radeon_fence *fence, bool interruptible);
 int radeon_fence_wait_next_locked(struct radeon_device *rdev, int ring);
-int radeon_fence_wait_empty_locked(struct radeon_device *rdev, int ring);
+void radeon_fence_wait_empty_locked(struct radeon_device *rdev, int ring);
 int radeon_fence_wait_any(struct radeon_device *rdev,
                           struct radeon_fence **fences,
                           bool intr);
diff --git a/drivers/gpu/drm/radeon/radeon_fence.c b/drivers/gpu/drm/radeon/radeon_fence.c
index 7b55625a5e18..be4e4f390e89 100644
--- a/drivers/gpu/drm/radeon/radeon_fence.c
+++ b/drivers/gpu/drm/radeon/radeon_fence.c
@@ -440,14 +440,11 @@ int radeon_fence_wait_any(struct radeon_device *rdev,
         return 0;
 }
 
+/* caller must hold ring lock */
 int radeon_fence_wait_next_locked(struct radeon_device *rdev, int ring)
 {
         uint64_t seq;
 
-        /* We are not protected by ring lock when reading current seq but
-         * it's ok as worst case is we return to early while we could have
-         * wait.
-         */
         seq = atomic64_read(&rdev->fence_drv[ring].last_seq) + 1ULL;
         if (seq >= rdev->fence_drv[ring].sync_seq[ring]) {
                 /* nothing to wait for, last_seq is
@@ -457,15 +454,27 @@ int radeon_fence_wait_next_locked(struct radeon_device *rdev, int ring)
         return radeon_fence_wait_seq(rdev, seq, ring, false, false);
 }
 
-int radeon_fence_wait_empty_locked(struct radeon_device *rdev, int ring)
+/* caller must hold ring lock */
+void radeon_fence_wait_empty_locked(struct radeon_device *rdev, int ring)
 {
-        /* We are not protected by ring lock when reading current seq
-         * but it's ok as wait empty is call from place where no more
-         * activity can be scheduled so there won't be concurrent access
-         * to seq value.
-         */
-        return radeon_fence_wait_seq(rdev, rdev->fence_drv[ring].sync_seq[ring],
-                                     ring, false, false);
+        uint64_t seq = rdev->fence_drv[ring].sync_seq[ring];
+
+        while(1) {
+                int r;
+                r = radeon_fence_wait_seq(rdev, seq, ring, false, false);
+                if (r == -EDEADLK) {
+                        mutex_unlock(&rdev->ring_lock);
+                        r = radeon_gpu_reset(rdev);
+                        mutex_lock(&rdev->ring_lock);
+                        if (!r)
+                                continue;
+                }
+                if (r) {
+                        dev_err(rdev->dev, "error waiting for ring to become"
+                                " idle (%d)\n", r);
+                }
+                return;
+        }
 }
 
 struct radeon_fence *radeon_fence_ref(struct radeon_fence *fence)