On Wed, 2011-04-27 at 10:32 +0200, Michel D?nzer wrote: > On Mit, 2011-04-27 at 16:10 +1000, christopher.halse.rogers at canonical.com > wrote: > > From: Christopher James Halse Rogers <christopher.halse.rogers at > > canonical.com> > > > > This is the least-bad behaviour. It means that we signal the > > vblank event before it actually happens, but since we're disabling > > vblanks there's no guarantee that it will *ever* happen otherwise. > > This may indeed be the best we can do for events that are pending when > the CRTC is disabled[0], but I can't see anything that would prevent new > events from getting scheduled (or synchronous vblank waits from timing > out) while the CRTC is disabled? > > [0] Though it might unnecessarily send events prematurely when the CRTC > is just disabled temporarily, e.g. as part of a modeset. > > > Also, this patch won't seem to help at all for other drivers which don't > call drm_vblank_off() directly when disabling a CRTC.
This is true. On the other hand, the other drivers don't wedge the vblank code into a state where vblanks cannot be re-enabled. So it's only a problem when disabling one of 2+ monitors on those drivers, whereas it's easily triggerable on single monitor systems on intel. > > Maybe it would be possible to move those calls to core code, and/or only > force sending out events when the CRTC isn't just getting disabled > temporarily. > As in: have the core modesetting code call drm_vblank_off before making the driver-specific calls when disabling a crtc? I'll look into it - that would appear to be a more general solution. It would be nice if the OML_sync_control had been written with a less than laser-like focus on the single monitor case, too. :/ -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 490 bytes Desc: This is a digitally signed message part URL: <http://lists.freedesktop.org/archives/dri-devel/attachments/20110427/4035b75e/attachment-0001.pgp>
