kms causes broken vsync with r600.

[rdxijn at yandex.ru]

16.04.10, 12:01, "Alex Deucher" <alexdeucher at gmail.com>:

> 2010/4/16  :
>  >
>  >
>  > 16.04.10, 10:58, "Alex Deucher" :
>  >
>  >> On Fri, Apr 16, 2010 at 10:16 AM,   wrote:
>  >>  >
>  >>  > Enabling kms with r600 causes serious problems with vsync. For example, glxgears with low-res window works just as there is no vsync, and with large window fps becomes 60, but visible and regular lags appear - rendering just stop approximately once a second for a sort moment.  EXAVSync options seems has no effect. Also there is following error when starting gl apps:
>  >>  >
>  >>  > do_wait: drmWaitVBlank returned -1, IRQs don't seem to be working correctly.
>  >>  > Try adjusting the vblank_mode configuration parameter.
>  >>  >
>  >>  > Adjusting vblank_mode var doesn't work ether. With ums there is no sync problem.
>  >>  >
>  >>
>  >>  those options are not supported under kms at the moment.
>  >>
>  >>  > I'm using Debian Squeeze with mesa 7.7.1-1 and radeon 6.13.0-1. Also i have two 1920x1080 panels connected via dvi.
>  >>
>  >>  What kernel are you using?  You need 2.6.33 for r6xx+ irq support
>  >>  which is required for vblank irqs.
>  >>
>  >>  Alex
>  >>
>  >>
>  >
>  > I've installed 2.6.33, there is indeed no drmWaitVBlank error, but the problem still exists.
>  >
>  
>  The dri_config vblank options don't work with kms.  you need to use
>  one of the GLX vsync extensions.
>  
>  Alex
>  
>  

Sorry, maybe i've described this bug in misleading way. The problem is not about enabled/disabled
vsync, but in that, that by the default with kms there are lags with buggy vsync. And i've find no way 
to change this buggy vsync state, ether proper enabling or disabling completely.