[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Vertical sync and KMS

On Sat, 2010-11-20 at 13:34 +0100, Sylvain Beucler wrote:
> Hi,
> Since the switch to KMS (Kernel Mode Setting) in the current Debian, I
> cannot get vertical sync to work with free 3D drivers.
> (Vertical syncs caps the game framerate to the physical screen's
> refresh rate, typically 60Hz, avoiding tearing and unnecessary display
> updates, and permitting smooth scrolling.)
> The only way to get vsync back is either use a proprietary driver or
> switch back to UMS (in either case: when that's actually possible).  I
> tried with 2 ATI Radeon cards and an Intel one, using a simple
> scrolling demo with bare OpenGL, SDL 1.3 and Pyglet.
> Do you get this issue in other distros, and do you know what's the
> cause?

It should work, for both radeon and intel, but I'm not sure if it's
supported in Mesa 7.8. You might need 7.9 from experimental.

Then either setting "vblank_mode=2" as an environment variable or or a
drirc configuration like the one below should give you vertical sync:

           <device screen="0" driver="dri2">
              <application name="Default">
                  <option name="vblank_mode" value="2" />

Sven Arvidsson
PGP Key ID 760BDD22

Attachment: signature.asc
Description: This is a digitally signed message part

Reply to: