[PATCH 1/3] drm/nouveau: wait for moving fence after pinning

[Daniel Vetter]

On Mon, Jun 21, 2021 at 03:03:26PM +0200, Christian König wrote:
> We actually need to wait for the moving fence after pinning
> the BO to make sure that the pin is completed.
> 
> Signed-off-by: Christian König <christian.koenig at amd.com>
> CC: stable at kernel.org
> ---
>  drivers/gpu/drm/nouveau/nouveau_prime.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/nouveau_prime.c b/drivers/gpu/drm/nouveau/nouveau_prime.c
> index 347488685f74..591738545eba 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_prime.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_prime.c
> @@ -93,7 +93,13 @@ int nouveau_gem_prime_pin(struct drm_gem_object *obj)
>  	if (ret)
>  		return -EINVAL;
>  
> -	return 0;
> +	if (nvbo->bo.moving) {

Don't we need to hold the dma_resv to read this? We can grab a reference
and then unlock, but I think just unlocked wait can go boom pretty easily
(since we don't hold a reference or lock so someone else can jump in and
free the moving fence).
-Daniel

> +		ret = dma_fence_wait(nvbo->bo.moving, true);
> +		if (ret)
> +			nouveau_bo_unpin(nvbo);
> +	}
> +
> +	return ret;
>  }
>  
>  void nouveau_gem_prime_unpin(struct drm_gem_object *obj)
> -- 
> 2.25.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch