[PATCH] present: Query the right CRTC to use each time

[Keith Packard]

Chris Wilson <chris at chris-wilson.co.uk> writes:

> (That the client can get confused and present on the wrong CRTC is
> an unfortunate race condition, but there needs to be a way to poll for
> XErrors alongside the futex signalling in order to catch when the futex
> will never be woken and abort.)

Perhaps we should actually signal the futex even if an error is
generated? That would be a bit unusual, but could avoid this problem.

> Right, looking again at the loop the error hits during the
> dri3_wait_for_msc() loop that doesn't break out the wait-for-event loop
> due to the BadMatch from xcb_present_notify_msc(). Another annoyance
> here is that for GetMSC we queue an event for the next vblank which
> seems like unwanted latency.

GetMSC should execute an immediate kernel call, not queue an event. Sounds
like it's doing something wrong...

-- 
keith.packard at intel.com
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 810 bytes
Desc: not available
URL: <http://lists.x.org/archives/xorg-devel/attachments/20140602/56136fd3/attachment.sig>