Am 28.03.22 um 15:35 schrieb philip yang:
On 2022-03-28 9:14 a.m., Christian König wrote:
Am 28.03.22 um 15:06 schrieb Philip Yang:
To fix two issues with unlocked update fence:
1. vm->last_unlocked store the latest fence without taking refcount.
2. amdgpu_vm_bo_update_mapping returns old fence, not the latest fence.
NAK, that code here is perfectly correct.
vm->last_unlocked gets a reference to the last unlocked operation.
Otherwise the last locked operation is added directly to the root
resv object.
Regards,
Christian.
Signed-off-by: Philip Yang <philip.y...@amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c | 2 +-
1 file changed, 1 insertion(+), 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 dbb551762805..69fba68ff88e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
@@ -109,7 +109,7 @@ static int amdgpu_vm_sdma_commit(struct
amdgpu_vm_update_params *p,
if (p->unlocked) {
struct dma_fence *tmp = dma_fence_get(f);
- swap(p->vm->last_unlocked, f);
+ swap(p->vm->last_unlocked, tmp);
dma_fence_put(tmp);
tmp is the new unlock fence, so this drop the new fence refcount, fix
is to move the old fence to tmp, drop the old fence refcount, take the
new fence reference.
f is return fence, because f swap to old fence, so old fence is
returned, not new fence, fix will not change f.
No, swap() will exchange the parameters a and b.
So tmp is pointing to the old fence when dma_fence_put() is called on it.
That reference counting is correct as far as I can see.
Regards,
Christian.
Regards,
Philip
} else {
amdgpu_bo_fence(p->vm->root.bo, f, true);
