[Bug 42035] no way to turn off vsync

[Michal Suchanek]

2011/10/26 Michel Dänzer <michel at daenzer.net>:
> On Die, 2011-10-25 at 20:41 +0200, Michal Suchanek wrote:
>> 2011/10/25 Michel Dänzer <michel at daenzer.net>:
>> > On Mon, 2011-10-24 at 23:23 +0200, Michal Suchanek wrote:
>> >> With this patch it should be at least possible to turn off all this
>> >> when it does not work.
>> >
>> > Exactly. So, have you had a chance to try it?
>>
>> I installed the packages I built yesterday. The patch has no visible effect.
>
> Well, I do see an effect in the log file:
>
> [2558366.995] (==) RADEON(0): SwapBuffers wait for vblank: disabled
>
>
>> > Does it address your bug report?
>>
>> I am not quite sure.
>
> The above means the thing the bug report complains about being
> impossible to disable is disabled.

Still it is disabled without the patch too, which it supposedly should not.

>
>> With the current Radeon driver ( xserver-xorg-video-radeon
>> 1:6.14.99+git20111024.856583db-0ubuntu0sarvatt~natty patched or not)
>> and X server 1.10.4 I could reliably reproduce a lockup on start of
>> glxgears on the primary screen with vsync enabled in drirc.
>
> That would be a different bug then. You could try finding out where
> things get stuck by attaching gdb to glxgears and/or the X server.

The trace shows it stuck in DRI2GetBuffersWithFormat.

Since the X server continues running I don't think I can figure out
where *that* is stuck.

Maybe a newer X server would behave differently, 1.10 is not exactly new.

Thanks

Michal