Commit c8af219d authored by Rob Clark's avatar Rob Clark
Browse files

drm/msm: Don't overwrite hw fence in hw_init 



Prior to the last commit, this could result in setting the GPU
written fence value back to an older value, if we had missed
updating completed_fence prior to suspend.  This was mostly
harmless as the GPU would eventually overwrite it again with
the correct value.  But we should just not do this.  Instead
just leave a sanity check that the fence looks plausible (in
case the GPU scribbled on memory).

Reported-by: default avatarSteev Klimaszewski <steev@kali.org>
Fixes: 95d1deb0 ("drm/msm/gem: Add fenced vma unpin")
Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
Tested-by: default avatarSteev Klimaszewski <steev@kali.org>
Patchwork: https://patchwork.freedesktop.org/patch/490138/
Link: https://lore.kernel.org/r/20220618161120.3451993-2-robdclark@gmail.com
parent 3c7a5221

drivers/gpu/drm/msm/adreno/adreno_gpu.c

+8 −3
Original line number Diff line number Diff line
@@ -498,10 +498,15 @@ int adreno_hw_init(struct msm_gpu *gpu) 


		ring->cur = ring->start;

		ring->next = ring->start;



		/* reset completed fence seqno: */

		ring->memptrs->fence = ring->fctx->completed_fence;

		ring->memptrs->rptr = 0;



		/* Detect and clean up an impossible fence, ie. if GPU managed

		 * to scribble something invalid, we don't want that to confuse

		 * us into mistakingly believing that submits have completed.

		 */

		if (fence_before(ring->fctx->last_fence, ring->memptrs->fence)) {

			ring->memptrs->fence = ring->fctx->last_fence;

		}

	}



	return 0;

drivers/gpu/drm/msm/msm_gpu.c

+1 −1
Original line number Diff line number Diff line
@@ -418,7 +418,7 @@ static void recover_worker(struct kthread_work *work) 
		 * one more to clear the faulting submit

		 */

		if (ring == cur_ring)

			fence++;

			ring->memptrs->fence = ++fence;



		msm_update_fence(ring->fctx, fence);

	}