On Wed, 27 Apr 2011 10:32:36 +0200 Michel D?nzer <michel at daenzer.net> 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. We should return -EINVAL in that case from drm_wait_vblank due to drm_vblank_get failing (i.e. the driver enable_vblank hook should fail if the corresponding crtc is off). At least that's how it's supposed to work. -- Jesse Barnes, Intel Open Source Technology Center
