[PATCH 4/4] drm/msm: always wait for the exclusive fence

[Daniel Vetter]

On Fri, Jul 02, 2021 at 01:16:42PM +0200, Christian König wrote:
> Drivers also need to to sync to the exclusive fence when
> a shared one is present.
> 
> Completely untested since the driver won't even compile on !ARM.

It's really not that hard to set up a cross-compiler, reasonable distros
have that now all packages. Does explain though why you tend to break the
arm build with drm-misc patches.

Please fix this.

> Signed-off-by: Christian König <christian.koenig at amd.com>

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> ---
>  drivers/gpu/drm/msm/msm_gem.c | 16 +++++++---------
>  1 file changed, 7 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
> index a94a43de95ef..72a07e311de3 100644
> --- a/drivers/gpu/drm/msm/msm_gem.c
> +++ b/drivers/gpu/drm/msm/msm_gem.c
> @@ -817,17 +817,15 @@ int msm_gem_sync_object(struct drm_gem_object *obj,
>  	struct dma_fence *fence;
>  	int i, ret;
>  
> -	fobj = dma_resv_shared_list(obj->resv);
> -	if (!fobj || (fobj->shared_count == 0)) {
> -		fence = dma_resv_excl_fence(obj->resv);
> -		/* don't need to wait on our own fences, since ring is fifo */
> -		if (fence && (fence->context != fctx->context)) {
> -			ret = dma_fence_wait(fence, true);
> -			if (ret)
> -				return ret;
> -		}
> +	fence = dma_resv_excl_fence(obj->resv);
> +	/* don't need to wait on our own fences, since ring is fifo */
> +	if (fence && (fence->context != fctx->context)) {
> +		ret = dma_fence_wait(fence, true);
> +		if (ret)
> +			return ret;
>  	}
>  
> +	fobj = dma_resv_shared_list(obj->resv);
>  	if (!exclusive || !fobj)
>  		return 0;
>  
> -- 
> 2.25.1
> 

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