drm/amdgpu: Force signal hw_fences that are embedded in non-sched jobs

[Why]
For engines not supporting soft reset, i.e. VCN, there will be a failed
ib test before mode 1 reset during asic reset. The fences in this case
are never signaled and next time when we try to free the sa_bo, kernel
will hang.

[How]
During pre_asic_reset, driver will clear job fences and afterwards the
fences' refcount will be reduced to 1. For drm_sched_jobs it will be
released in job_free_cb, and for non-sched jobs like ib_test, it's meant
to be released in sa_bo_free but only when the fences are signaled. So
we have to force signal the non_sched bad job's fence during
pre_asic_reset or the clear is not complete.

Signed-off-by: YuBiao Wang <[email protected]>
Acked-by: Luben Tuikov <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

Author: YuBiao Wang

drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c

@@ -678,6 +678,15 @@ void amdgpu_fence_driver_clear_job_fences(struct amdgpu_ring *ring)
 		ptr = &ring->fence_drv.fences[i];
 		old = rcu_dereference_protected(*ptr, 1);
 		if (old && old->ops == &amdgpu_job_fence_ops) {
+			struct amdgpu_job *job;
+
+			/* For non-scheduler bad job, i.e. failed ib test, we need to signal
+			 * it right here or we won't be able to track them in fence_drv
+			 * and they will remain unsignaled during sa_bo free.
+			 */
+			job = container_of(old, struct amdgpu_job, hw_fence);
+			if (!job->base.s_fence && !dma_fence_is_signaled(old))
+				dma_fence_signal(old);
 			RCU_INIT_POINTER(*ptr, NULL);
 			dma_fence_put(old);
 		}