Quoting Daniel Vetter (2018-05-04 09:57:59) > On Fri, May 04, 2018 at 09:31:33AM +0100, Chris Wilson wrote: > > Quoting Daniel Vetter (2018-05-04 09:23:01) > > > On Fri, May 04, 2018 at 10:17:22AM +0200, Daniel Vetter wrote: > > > > 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. > > > > > > I also think clearer separation between optional optimization hooks and > > > mandatory core parts is useful in itself. > > > > A new spelling of midlayer ;) I don't see the contradiction with a > > driver saying use the default and simplicity. (I know which one the > > compiler thinks is simpler ;) > > If the compiler overhead is real then I guess it would makes to be > explicit. I don't expect that to be a problem though for a blocking > function. > > I disagree on this being a midlayer - you can still overwrite everything > you please to. What it does help is people doing less copypasting (and > assorted bugs), at least in the grand scheme of things. And we do have a > _lot_ more random small drivers than just a few years ago. Reducing the > amount of explicit typing just to get default bahaviour has been an > ongoing theme for a few years now, and your objection here is about the > first that this is not a good idea. So I'm somewhat confused. I'm just saying I don't see any rationale for this patch. "Almost everyone uses dma_fence_default_wait." Why change? Making it look simpler on the surface, so that you don't have to think about things straight away? I understand the appeal, but I do worry about it just being an illusion. (Cutting and pasting a line saying .wait = default_wait, doesn't feel that onerous, as you likely cut and paste the ops anyway, and at the very least you are reminded about some of the interactions. You could even have default initializers and/or magic macros to hide the cut and paste; maybe a simple_dma_fence [now that's a midlayer!] but I haven't looked.) -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
