On 2018-12-20 6:16 p.m., Michel Dänzer wrote: > On 2018-12-20 6:09 p.m., Daniel Vetter wrote: >> On Thu, Dec 20, 2018 at 6:03 PM Alex Deucher <alexdeucher@xxxxxxxxx> wrote: >>> On Thu, Dec 20, 2018 at 11:54 AM Daniel Vetter <daniel@xxxxxxxx> wrote: >> >>>> Not sure about the gamma thing since we had opposite bugs on i915 >>>> about gamma not being vsynced and tearing terribly. Cursor is special >>>> since it tends to be too small to notice tearing. >>> >>> Our cursor hw (and possibly gamma as well Nicholas? Harry?) is double >>> buffered, so we can update it any time for the most part and the >>> changes won't take affect until the next vupdate period. >> >> Hm, I guess we could make the gamma update optionally async, and let >> drivers deal. The issue is that the current async helper stuff won't >> cope with gamma updates (it's aimed at plane updates only, not at crtc >> property updates). Or we get userspace to do proper atomic updates. Or >> we do some faking in the kernel, e.g. waiting with the gamma update >> until the next atomic update happens. But that kinda breaks >> ->atomic_check. > > Would it be possible to merge gamma changes into a pending commit, if > there is one, and create a new commit otherwise? > > Otherwise the atomic API just moves this same problem to be solved by > userspace. Actually, I'm not sure this is even solvable in a Xorg driver. When it gets called to update the gamma LUT: 1. If there's a pending atomic commit, it cannot amend that, can it? 2. It has no way of knowing when the next atomic commit would be submitted e.g. for a page flip, so it kind of has to create its own commit for the gamma update. -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
