From: Rob Clark robdclark@chromium.org
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: Steev Klimaszewski steev@kali.org Fixes: 95d1deb02a9c ("drm/msm/gem: Add fenced vma unpin") Signed-off-by: Rob Clark robdclark@chromium.org --- drivers/gpu/drm/msm/adreno/adreno_gpu.c | 11 ++++++++--- drivers/gpu/drm/msm/msm_gpu.c | 2 +- 2 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c index e1aef4875e2f..dd044d557c7c 100644 --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c @@ -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; diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c index b61078f0cd0f..8c00f9187c03 100644 --- a/drivers/gpu/drm/msm/msm_gpu.c +++ b/drivers/gpu/drm/msm/msm_gpu.c @@ -430,7 +430,7 @@ 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); }