Re: [PATCH 6/8] dma-buf: use inline lock for the stub fence v2

[Boris Brezillon <boris.brezillon@collabora.com>]

On Tue, 10 Feb 2026 11:02:01 +0100
"Christian König" <ckoenig.leichtzumerken@gmail.com> wrote:

> Using the inline lock is now the recommended way for dma_fence
> implementations.
> 
> So use this approach for the framework's internal fences as well.
> 
> Also saves about 4 bytes for the external spinlock.
> 
> v2: drop unnecessary changes
> 
> Signed-off-by: Christian König <christian.koenig@amd.com>
> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
> Reviewed-by: Philipp Stanner <phasta@kernel.org>

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>

> ---
>  drivers/dma-buf/dma-fence.c | 12 ++----------
>  1 file changed, 2 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
> index 1833889e7466..541e20aa4e6c 100644
> --- a/drivers/dma-buf/dma-fence.c
> +++ b/drivers/dma-buf/dma-fence.c
> @@ -24,7 +24,6 @@ EXPORT_TRACEPOINT_SYMBOL(dma_fence_emit);
>  EXPORT_TRACEPOINT_SYMBOL(dma_fence_enable_signal);
>  EXPORT_TRACEPOINT_SYMBOL(dma_fence_signaled);
>  
> -static DEFINE_SPINLOCK(dma_fence_stub_lock);
>  static struct dma_fence dma_fence_stub;
>  
>  /*
> @@ -123,12 +122,9 @@ static const struct dma_fence_ops dma_fence_stub_ops = {
>  
>  static int __init dma_fence_init_stub(void)
>  {
> -	dma_fence_init(&dma_fence_stub, &dma_fence_stub_ops,
> -		       &dma_fence_stub_lock, 0, 0);
> -
> +	dma_fence_init(&dma_fence_stub, &dma_fence_stub_ops, NULL, 0, 0);
>  	set_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT,
>  		&dma_fence_stub.flags);
> -
>  	dma_fence_signal(&dma_fence_stub);
>  	return 0;
>  }
> @@ -160,11 +156,7 @@ struct dma_fence *dma_fence_allocate_private_stub(ktime_t timestamp)
>  	if (fence == NULL)
>  		return NULL;
>  
> -	dma_fence_init(fence,
> -		       &dma_fence_stub_ops,
> -		       &dma_fence_stub_lock,
> -		       0, 0);
> -
> +	dma_fence_init(fence, &dma_fence_stub_ops, NULL, 0, 0);
>  	set_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT,
>  		&fence->flags);
>