[Bug 42035] no way to turn off vsync

[Michal Suchanek]

2011/10/24 Michel Dänzer <michel at daenzer.net>:
> On Mon, 2011-10-24 at 14:00 +0200, Michal Suchanek wrote:
>> 2011/10/24 Michel Dänzer <michel at daenzer.net>:
>> > On Don, 2011-10-20 at 12:16 +0200, Michal Suchanek wrote:
>> >>
>> >> On 20 October 2011 11:38,  <bugzilla-daemon at freedesktop.org> wrote:
>> >> > https://bugs.freedesktop.org/show_bug.cgi?id=42035
>> >> >
>> >> > --- Comment #1 from Michel Dänzer <michel at daenzer.net> 2011-10-20 02:38:29 PDT ---
>> >> >> This should be runtime configurable, preferably per-application like dri.
>> >> >
>> >> > That would require some xserver dri2 changes first, to allow the driver to tell
>> >> > the different cases apart. There's been some discussion about this on the
>> >> > xorg-devel list, started by Chris Wilson.
>> >>
>> >> Anyone can point at the discussion or say what the problem is with this?
>> >
>> > Actually, the radeon driver patch below might be good enough, at least
>> > for now. It disables Option "SwapBuffersWait" by default when the real
>> > sync-to-vblank functionality is working. There should be no need for the
>> > vline waits for DRI2 in that case.
>> >
>> > Thoughts
>>
>> Is it possible to determine if the option is on or off?
>>
>> Or does it produce some log messages saying what it enables based on what?
>
> You're welcome to try it yourself. ;) Anyway, the updated patch below shows

I am asking this because my experiments with glxgears  without the
patch show vrefresh limited fps, fps unlimited by vrefresh, and 0 fps
depending on some variables like what screen the window is on, if the
window is mapped or not, if the screen is blanked or not, and current
phase of the Moon or some other variable I can't figure out.

Thanks

Michal