Re: [PATCH] drm/amdgpu: fix invalid fence handling in amdgpu_vm_tlb_flush

[Christian König]

Am 02.09.24 um 05:03 schrieb Lang Yu:
Fixes: 5a1c27951966 ("drm/amdgpu: implement TLB flush fence")
Signed-off-by: Lang Yu <lang...@amd.com>

Ah yes, that explains why CPU based updates doesn't work reliable any more.

You need to add some explanation to the commit message, e.g. something 
like "CPU based updates doesn't produce a fence."

With that done Reviewed-by: Christian König <christian.koe...@amd.com>

---
  drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 6 ++++--
  1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 1d46a5c81ec4..f93804902fd3 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -908,10 +908,12 @@ amdgpu_vm_tlb_flush(struct amdgpu_vm_update_params 
*params,
  {
        struct amdgpu_vm *vm = params->vm;
  
-	if (!fence || !*fence)
+       tlb_cb->vm = vm;
+       if (!fence || !*fence) {
+               amdgpu_vm_tlb_seq_cb(NULL, &tlb_cb->cb);
                return;
+       }
  
-	tlb_cb->vm = vm;
        if (!dma_fence_add_callback(*fence, &tlb_cb->cb,
                                    amdgpu_vm_tlb_seq_cb)) {
                dma_fence_put(vm->last_tlb_flush);