[Intel-gfx] vsync problems with recent graphics stack and 945gm

[Jesse Barnes]

On Mon, 13 Sep 2010 23:36:11 +0300
Vasily Khoruzhick <anarsoul at gmail.com> wrote:

> Hi there, I've just built graphics stack (xf86-video-intel, libdrm, mesa) from 
> git (but I'm on 2.6.35.x kernel) and still experiencing vsync troubles without 
> composite manager, here's output of glxgears:
> 
> $ glxgears
> Running synchronized to the vertical refresh.  The framerate should be
> approximately the same as the monitor refresh rate.
> 243 frames in 5.0 seconds = 48.124 FPS
> 157 frames in 5.0 seconds = 31.300 FPS
> 155 frames in 5.0 seconds = 30.864 FPS
> 
> But I'm pretty sure that vertical refresh is 60 hz! And gears are jerky (not 
> smooth at all). If I move mouse cursor over glxgears window FPS goes up to 60. 
> And main problem is that keyboard events are also jerky, i.e. I press key and 
> system receives press event in 0.1-0.5 sec or so (tested via xev).
> 
> There's no such problem when composition manager is running (i.e. effects are 
> enabled in KDE)
> 
> Is there any solution for this problem? It really annoys me.

I remember seeing a similar problem on an Eee PC I had; it seemed to be
timer/interrupt related somehow.  If I booted with clocksource=tsc
(or maybe it was pit) I got nice smooth animations, but if I used the
HPET things were really slow.

Does the same work for you?

-- 
Jesse Barnes, Intel Open Source Technology Center