2011/10/28 Michel Dänzer <[email protected]>: > On Don, 2011-10-27 at 23:47 +0200, Michal Suchanek wrote: >> 2011/10/27 Michal Suchanek <[email protected]>: >> > 2011/10/27 Michel Dänzer <[email protected]>: >> >> On Mit, 2011-10-26 at 21:36 +0200, Michal Suchanek wrote: >> >>> >> >>> Ideally I would like no tearing and no vblank sync >> >>> but both tearing prevention in the radeon driver and sync to vblank >> >>> can lead to applications getting stuck in the X server. >> >> >> >> Please provide details about a specific scenario where this happens with >> >> vblank_mode=0. >> > >> > Remove all configuration pertaining to vsync/vline wait. >> > >> > Run recent radeon driver on 3.0.0-10 Ubuntu kernel. >> > >> > Run glxgears. They won't render even a single frame unless the screen >> > is rotated. >> >> Hmm, it does not depend on kernel version. >> >> When two X servers are running the second one gets the stuck applications. > > Ah! Assuming the first server is running GL clients, that's probably the > problem described in > http://lists.freedesktop.org/archives/dri-devel/2011-October/015677.html , > starting with 'Also note that running drm_wait_ioctl as DRM_LOCKED is a > severe problem that we have to address quickly'. >
Normally only one at a time but there is aiglx and whatnot. Also while the second X server gets applications stuck on start the first gets them stuck on screen blank. So behaviour varies per X server instance, too. Your patch comes handy because with vline waits disabled I can start glxgears even if they would get stuck otherwise by configuring .drirc. > >> >>> In the more recent snapshot the tearing prevention is not working >> >>> which is probably a bug in itself. >> >> >> >> Define 'not working'. >> > >> > fullscreen glxgears fps are not capped to the screen refresh rate. >> >> With the current kernel and driver it seems to work more consistently. >> >> Always synced on non-rotated screen and never synced on rotated, mapped or >> not. >> >> At least fresh after booting. There seems to be some period about two >> weeks long in which the behaviour may vary :-S > > Variance over time sounds like counter wraparound issues, but those > shouldn't affect vline waits... I only saw vline waits ever affected. That does not mean vblanks waits aren't. I did not run X server with vline waits off for an extended period of time yet. However, both vline waits and vblank waits get stuck in the same X client call. Thanks Michal _______________________________________________ xorg-driver-ati mailing list [email protected] http://lists.x.org/mailman/listinfo/xorg-driver-ati
