Re: [Linaro-mm-sig] [PATCH 04/15] dma-fence: Make ->wait callback optional

On Fri, May 04, 2018 at 09:09:10AM +0100, Chris Wilson wrote:

Quoting Daniel Vetter (2018-05-03 15:25:52)

...

Almost everyone uses dma_fence_default_wait.

v2: Also remove the BUG_ON(!ops->wait) (Chris).

I just don't get the rationale for implicit over explicit.

Closer approximation of dwim semantics. There's been tons of patch series all over drm and related places to get there, once we have a big pile of implementations and know what the dwim semantics should be. Individually they're all not much, in aggregate they substantially simplify simple drivers. -Daniel