[PATCH 1/2] drm//amdgpu: Always sync fence before unlock eviction_lock

[Christian König]

Am 13.03.20 um 08:43 schrieb xinhui pan:
> The fence generated in ->commit is a shared one, so add it to resv.
> And we need do that with eviction lock hold.
>
> Currently we only sync last_direct/last_delayed before ->prepare. But we
> fail to sync the last fence generated by ->commit. That cuases problems
> if eviction happenes later, but it does not sync the last fence.

NAK, that won't work.

We can only add fences when the dma_resv object is locked and that is 
only the case when validating.

I'm considering to just partially revert the patch originally stopping 
to add fences and instead only not add them when invalidating in a 
direct submit.

Christian.

>
> Cc: Christian König <christian.koenig at amd.com>
> Cc: Alex Deucher <alexander.deucher at amd.com>
> Cc: Felix Kuehling <Felix.Kuehling at amd.com>
> Signed-off-by: xinhui pan <xinhui.pan at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 9 +++++++--
>   1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index 73398831196f..f424b5969930 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -1582,6 +1582,7 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
>   	struct amdgpu_vm_update_params params;
>   	enum amdgpu_sync_mode sync_mode;
>   	int r;
> +	struct amdgpu_bo *root = vm->root.base.bo;
>   
>   	memset(&params, 0, sizeof(params));
>   	params.adev = adev;
> @@ -1604,8 +1605,6 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
>   	}
>   
>   	if (flags & AMDGPU_PTE_VALID) {
> -		struct amdgpu_bo *root = vm->root.base.bo;
> -
>   		if (!dma_fence_is_signaled(vm->last_direct))
>   			amdgpu_bo_fence(root, vm->last_direct, true);
>   
> @@ -1623,6 +1622,12 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
>   
>   	r = vm->update_funcs->commit(&params, fence);
>   
> +	if (!dma_fence_is_signaled(vm->last_direct))
> +		amdgpu_bo_fence(root, vm->last_direct, true);
> +
> +	if (!dma_fence_is_signaled(vm->last_delayed))
> +		amdgpu_bo_fence(root, vm->last_delayed, true);
> +
>   error_unlock:
>   	amdgpu_vm_eviction_unlock(vm);
>   	return r;