[Intel-gfx] [PATCH 01/40] drm: Use default dma_fence hooks where possible for null syncobj

[Tvrtko Ursulin]

On 19/09/2018 20:55, Chris Wilson wrote:
> Both the .enable_signaling and .release of the null syncobj fence
> can be replaced by the default callbacks for a small reduction in code
> size.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   drivers/gpu/drm/drm_syncobj.c | 11 -----------
>   1 file changed, 11 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
> index 497729202bfe..e254f97fed7d 100644
> --- a/drivers/gpu/drm/drm_syncobj.c
> +++ b/drivers/gpu/drm/drm_syncobj.c
> @@ -66,20 +66,9 @@ static const char *drm_syncobj_stub_fence_get_name(struct dma_fence *fence)
>           return "syncobjstub";
>   }
>   
> -static bool drm_syncobj_stub_fence_enable_signaling(struct dma_fence *fence)
> -{
> -    return !dma_fence_is_signaled(fence);
> -}
> -
> -static void drm_syncobj_stub_fence_release(struct dma_fence *f)
> -{
> -	kfree(f);
> -}

With the default implementation this becomes kfree_rcu - so 
theoretically a change in behaviour after all.

Since there are RCU usages in syncobj and the magical null/stub handle 
is not explained (or I did not find it), was the code fine with a plain 
kfree?

Regards,

Tvrtko

>   static const struct dma_fence_ops drm_syncobj_stub_fence_ops = {
>   	.get_driver_name = drm_syncobj_stub_fence_get_name,
>   	.get_timeline_name = drm_syncobj_stub_fence_get_name,
> -	.enable_signaling = drm_syncobj_stub_fence_enable_signaling,
> -	.release = drm_syncobj_stub_fence_release,
>   };
>   
>   
>