Hi, On Wed, 15 Jul 2020 at 12:05, Bas Nieuwenhuizen <bas@xxxxxxxxxxxxxxxxxxx> wrote: > On Wed, Jul 15, 2020 at 12:34 PM Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: > > Maybe now is the time to ask: are you using sw_sync outside of > > validation? > > Yes, this is used as part of the Android stack on Chrome OS (need to > see if ChromeOS specific, but > https://source.android.com/devices/graphics/sync#sync_timeline > suggests not) Android used to mandate it for their earlier iteration of release fences, which was an empty/future fence having no guarantee of eventual forward progress until someone committed work later on. For example, when you committed a buffer to SF, it would give you an empty 'release fence' for that buffer which would only be tied to work to signal it when you committed your _next_ buffer, which might never happen. They removed that because a) future fences were a bad idea, and b) it was only ever useful if you assumed strictly FIFO/round-robin return order which wasn't always true. So now it's been watered down to 'use this if you don't have a hardware timeline', but why don't we work with Android people to get that removed entirely? Cheers, Daniel _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
