Hi Christian,
On 2022-10-14 04:15, Christian König wrote:
> Make sure that we always have a CPU round trip to let the submission
> code correctly decide if a TLB flush is necessary or not.
>
> Signed-off-by: Christian König <christian.koenig@xxxxxxx>
> CC: stable@xxxxxxxxxxxxxxx # 5.19+
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
> index 2b0669c464f6..69e105fa41f6 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
> @@ -116,8 +116,15 @@ static int amdgpu_vm_sdma_commit(struct amdgpu_vm_update_params *p,
> DMA_RESV_USAGE_BOOKKEEP);
> }
>
> - if (fence && !p->immediate)
> + if (fence && !p->immediate) {
> + /*
> + * Most hw generations now have a separate queue for page table
> + * updates, but when the queue is shared with userspace we need
> + * the extra CPU round trip to correctly flush the TLB.
> + */
> + set_bit(DRM_SCHED_FENCE_DONT_PIPELINE, &f->flags);
> swap(*fence, f);
> + }
Do you ever turn that bit off?
Regards
Luben
> dma_fence_put(f);
> return 0;
>
