drm/radeon: avoid deadlock in pm path when waiting for fence
radeon_fence_wait_empty_locked should not trigger GPU reset as no
place where it's call from would benefit from such thing and it
actually lead to a kernel deadlock in case the reset is triggered
from pm codepath. Instead force ring completion in place where it
makes sense or return early in others.
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
diff --git a/drivers/gpu/drm/radeon/radeon_fence.c b/drivers/gpu/drm/radeon/radeon_fence.c
index a9b0fa5..3435625 100644
--- a/drivers/gpu/drm/radeon/radeon_fence.c
+++ b/drivers/gpu/drm/radeon/radeon_fence.c
@@ -609,26 +609,20 @@
* Returns 0 if the fences have passed, error for all other cases.
* Caller must hold ring lock.
*/
-void radeon_fence_wait_empty_locked(struct radeon_device *rdev, int ring)
+int radeon_fence_wait_empty_locked(struct radeon_device *rdev, int ring)
{
uint64_t seq = rdev->fence_drv[ring].sync_seq[ring];
+ int r;
- while(1) {
- int r;
- r = radeon_fence_wait_seq(rdev, seq, ring, false, false);
+ r = radeon_fence_wait_seq(rdev, seq, ring, false, false);
+ if (r) {
if (r == -EDEADLK) {
- mutex_unlock(&rdev->ring_lock);
- r = radeon_gpu_reset(rdev);
- mutex_lock(&rdev->ring_lock);
- if (!r)
- continue;
+ return -EDEADLK;
}
- if (r) {
- dev_err(rdev->dev, "error waiting for ring to become"
- " idle (%d)\n", r);
- }
- return;
+ dev_err(rdev->dev, "error waiting for ring[%d] to become idle (%d)\n",
+ ring, r);
}
+ return 0;
}
/**
@@ -854,13 +848,17 @@
*/
void radeon_fence_driver_fini(struct radeon_device *rdev)
{
- int ring;
+ int ring, r;
mutex_lock(&rdev->ring_lock);
for (ring = 0; ring < RADEON_NUM_RINGS; ring++) {
if (!rdev->fence_drv[ring].initialized)
continue;
- radeon_fence_wait_empty_locked(rdev, ring);
+ r = radeon_fence_wait_empty_locked(rdev, ring);
+ if (r) {
+ /* no need to trigger GPU reset as we are unloading */
+ radeon_fence_driver_force_completion(rdev);
+ }
wake_up_all(&rdev->fence_queue);
radeon_scratch_free(rdev, rdev->fence_drv[ring].scratch_reg);
rdev->fence_drv[ring].initialized = false;