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

1 files changed, 12 insertions, 3 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_pm.c b/drivers/gpu/drm/radeon/radeon_pm.c
index aa14dbb7e4fb..0bfa656aa87d 100644
--- a/drivers/gpu/drm/radeon/radeon_pm.c
+++ b/drivers/gpu/drm/radeon/radeon_pm.c
@@ -234,7 +234,7 @@ static void radeon_set_power_state(struct radeon_device *rdev)
 
 static void radeon_pm_set_clocks(struct radeon_device *rdev)
 {
-        int i;
+        int i, r;
 
         /* no need to take locks, etc. if nothing's going to change */
         if ((rdev->pm.requested_clock_mode_index == rdev->pm.current_clock_mode_index) &&
@@ -248,8 +248,17 @@ static void radeon_pm_set_clocks(struct radeon_device *rdev)
         /* wait for the rings to drain */
         for (i = 0; i < RADEON_NUM_RINGS; i++) {
                 struct radeon_ring *ring = &rdev->ring[i];
-                if (ring->ready)
-                        radeon_fence_wait_empty_locked(rdev, i);
+                if (!ring->ready) {
+                        continue;
+                }
+                r = radeon_fence_wait_empty_locked(rdev, i);
+                if (r) {
+                        /* needs a GPU reset dont reset here */
+                        mutex_unlock(&rdev->ring_lock);
+                        up_write(&rdev->pm.mclk_lock);
+                        mutex_unlock(&rdev->ddev->struct_mutex);
+                        return;
+                }
         }
 
         radeon_unmap_vram_bos(rdev);