Hi Adam, On 24 April 2018 at 20:52, Adam Jackson <a...@nwnk.net> wrote: > On Tue, 2018-04-24 at 11:42 +0100, Daniel Stone wrote: >> On 24 April 2018 at 09:17, Mario Kleiner <mario.kleiner...@gmail.com> wrote: >> > Both xf86-video-intel and xf86-video-nouveau cause OpenGL >> > clients to fail when used with DRI3 on server 1.20 with Mesa 18.1. >> > >> > Reason is that the servers DRI3 version is now unconditionally >> > reported as DRI3 1.2 to 1.2 capable clients. This causes clients >> > using Mesa 18.1 to use the new DRI 3.2 requests DRI3GetSupportedModifiers, >> > DRI3PixmapFromBuffers, etc. Drivers other than modesetting-ddx >> > do not support the needed hooks like info->pixmap_from_fds or >> > info->get_formats, info->get_modifiers. Unfortunately we can't >> > simply report the servers DRI3 version as 1.0 in this case, as >> > the reported version can not be specific to a X-Screen, and >> > different screens may have drivers with different capabilities. > > I think this implies we should not advertise 1.2 if any screen lacks > the 1.2 hooks.
To be honest, I'd be fine with that too. >> Thanks a lot for hunting this down! This fix does still make me >> uncomfortable though. I think a better fix would be, on the Mesa side, >> to never call any 1.2 codepaths for the server if we get no >> formats/modifiers back from the GetSupported calls, and to never call >> any 1.2 codepaths for the drawable if DRIImage's >> createImageWithModifiers does not exist or if it fails and we fall >> back to regular createImage. That way we make sure that both sides >> exercise the same behaviour: either both with explicit modifiers, or >> neither. > > The problem with that strategy is it means 1.20 would be compatible > with zero already-released versions of Mesa. True, though it is only 18.1.0rc1 broken now, and we've plenty of time before rc2. Cheers, Daniel _______________________________________________ xorg-devel@lists.x.org: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: https://lists.x.org/mailman/listinfo/xorg-devel