Am 05.05.23 um 14:44 schrieb Lang Yu:
When using cpu to update page tables, vm update fences are unused.
Install stub fence into these fence pointers instead of NULL
to avoid NULL dereference when calling dma_fence_wait() on them.
Suggested-by: Christian König <christian.koenig@xxxxxxx>
Signed-off-by: Lang Yu <Lang.Yu@xxxxxxx>
Reviewed-by: Christian König <christian.koenig@xxxxxxx>
---
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 78daf6e2f337..aae70a16fd46 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -1444,6 +1444,7 @@ struct amdgpu_bo_va *amdgpu_vm_bo_add(struct amdgpu_device *adev,
amdgpu_vm_bo_base_init(&bo_va->base, vm, bo);
bo_va->ref_count = 1;
+ bo_va->last_pt_update = dma_fence_get_stub();
INIT_LIST_HEAD(&bo_va->valids);
INIT_LIST_HEAD(&bo_va->invalids);
@@ -2144,7 +2145,8 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm)
vm->update_funcs = &amdgpu_vm_cpu_funcs;
else
vm->update_funcs = &amdgpu_vm_sdma_funcs;
- vm->last_update = NULL;
+
+ vm->last_update = dma_fence_get_stub();
vm->last_unlocked = dma_fence_get_stub();
vm->last_tlb_flush = dma_fence_get_stub();
vm->generation = 0;
@@ -2267,7 +2269,7 @@ int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm)
goto unreserve_bo;
dma_fence_put(vm->last_update);
- vm->last_update = NULL;
+ vm->last_update = dma_fence_get_stub();
vm->is_compute_context = true;
/* Free the shadow bo for compute VM */
