Hi,

There's only one exclusive slot, and we must not break the ordering. Adding a new exclusive fence drops all previous fences from the dma_resv. To avoid violating the signalling order we err on the side of over-synchronizing by waiting for the existing fences, even if userspace asked us to ignore them.

A better fix would be to us a dma_fence_chain or _array like e.g. amdgpu now uses, but it probably makes sense to lift this into dma-resv.c code as a proper concept, so that drivers don't have to hack up their own solution each on their own. Hence go with the simple fix for now.

I find a typo in the commit message, us -> use