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

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