A circular locking dependency was detected between the global `adev->userq_mutex` and per-file `userq_mgr->userq_mutex` when creating user queues. The issue occurs because:
1. `amdgpu_userq_suspend()`and `amdgpu_userq_resume` take `adev->userq_mutex` first, then `userq_mgr->userq_mutex` 2. While `amdgpu_userq_create()` takes them in reverse order This patch resolves the issue by: 1. Moving the `adev->userq_mutex` lock earlier in `amdgpu_userq_create()` to cover the `amdgpu_userq_ensure_ev_fence()` call 2. Releasing it after we're done with queue creation 3. Maintaining consistent lock ordering (adev->userq_mutex always before userq_mgr->userq_mutex) in all code paths Signed-off-by: Jesse Zhang <[email protected]> --- drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c index 697dd3cbd114..6ba3c0b14279 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c @@ -531,6 +531,7 @@ amdgpu_userq_create(struct drm_file *filp, union drm_amdgpu_userq *args) * * This will also make sure we have a valid eviction fence ready to be used. */ + mutex_lock(&adev->userq_mutex); amdgpu_userq_ensure_ev_fence(&fpriv->userq_mgr, &fpriv->evf_mgr); uq_funcs = adev->userq_funcs[args->in.ip_type]; @@ -594,7 +595,6 @@ amdgpu_userq_create(struct drm_file *filp, union drm_amdgpu_userq *args) } /* don't map the queue if scheduling is halted */ - mutex_lock(&adev->userq_mutex); if (adev->userq_halt_for_enforce_isolation && ((queue->queue_type == AMDGPU_HW_IP_GFX) || (queue->queue_type == AMDGPU_HW_IP_COMPUTE))) @@ -613,13 +613,13 @@ amdgpu_userq_create(struct drm_file *filp, union drm_amdgpu_userq *args) goto unlock; } } - mutex_unlock(&adev->userq_mutex); args->out.queue_id = qid; unlock: mutex_unlock(&uq_mgr->userq_mutex); + mutex_unlock(&adev->userq_mutex); return r; } -- 2.49.0
