6.17-stable review patch. If anyone has any objections, please let me know.
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From: Robert McClinton rbmccav@gmail.com
commit 9eb00b5f5697bd56baa3222c7a1426fa15bacfb5 upstream.
Delete the attempt to progress the queue when checking if fence is signaled. This avoids deadlock.
dma-fence_ops::signaled can be called with the fence lock in unknown state. For radeon, the fence lock is also the wait queue lock. This can cause a self deadlock when signaled() tries to make forward progress on the wait queue. But advancing the queue is unneeded because incorrectly returning false from signaled() is perfectly acceptable.
Link: https://github.com/brave/brave-browser/issues/49182 Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4641 Cc: Alex Deucher alexander.deucher@amd.com Signed-off-by: Robert McClinton rbmccav@gmail.com Signed-off-by: Alex Deucher alexander.deucher@amd.com (cherry picked from commit 527ba26e50ec2ca2be9c7c82f3ad42998a75d0db) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/radeon/radeon_fence.c | 7 ------- 1 file changed, 7 deletions(-)
--- a/drivers/gpu/drm/radeon/radeon_fence.c +++ b/drivers/gpu/drm/radeon/radeon_fence.c @@ -360,13 +360,6 @@ static bool radeon_fence_is_signaled(str if (atomic64_read(&rdev->fence_drv[ring].last_seq) >= seq) return true;
- if (down_read_trylock(&rdev->exclusive_lock)) { - radeon_fence_process(rdev, ring); - up_read(&rdev->exclusive_lock); - - if (atomic64_read(&rdev->fence_drv[ring].last_seq) >= seq) - return true; - } return false; }