[PATCH 02/25] dma-fence: prime lockdep annotations

[Jason Gunthorpe]

On Thu, Jul 09, 2020 at 10:09:11AM +0200, Daniel Vetter wrote:
> Hi Jason,
> 
> Below the paragraph I've added after our discussions around dma-fences
> outside of drivers/gpu. Good enough for an ack on this, or want something
> changed?
> 
> Thanks, Daniel
> 
> > + * Note that only GPU drivers have a reasonable excuse for both requiring
> > + * &mmu_interval_notifier and &shrinker callbacks at the same time as having to
> > + * track asynchronous compute work using &dma_fence. No driver outside of
> > + * drivers/gpu should ever call dma_fence_wait() in such contexts.

I was hoping we'd get to 'no driver outside GPU should even use
dma_fence()'

Is that not reasonable?

When your annotations once anything uses dma_fence it has to assume
the worst cases, right?

Jason