[RFC PATCH] dma-buf/dma-fence: Use a successful read_trylock() annotation for dma_fence_begin_signalling()

[Thomas Hellström]

On 4/28/23 14:52, Thomas Hellström wrote:
> Condsider the following call sequence:
>
> /* Upper layer */
> dma_fence_begin_signalling();
> lock(tainted_shared_lock);
> /* Driver callback */
> dma_fence_begin_signalling();
> ...

The "Upper layer" here currently being the drm scheduler and "Driver 
callback" being an xe scheduler callback.

While opt-in annotating the drm scheduler would achieve the same result, 
I think this patch should be considered anyway, as I don't think we will 
miss any true lockdep violations as a result of it.

/Thomas