Am 17.10.22 um 07:29 schrieb Luben Tuikov:
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?
No, I just rely on the fact that the flags are zero initialized.
Regards,
Christian.
Regards
Luben
dma_fence_put(f);
return 0;
