[Bug 42035] no way to turn off vsync

[Michel Dänzer]

On Don, 2011-10-27 at 01:14 +0200, Michal Suchanek wrote:
> 
> The primary screen is not rotated, the secondary is.

In the future, please mention 'details' like that up front. Rotation
makes things quite a bit more complicated. 


> Window last mapped on primary screen (or the secondary when I turn off
> rotation) keeps capped by the screen refresh rate when unmapped.

radeon_dri2_drawable_crtc() only looks at the window position, not at
whether it's currently mapped. We could change it to return -1 for
unmapped windows, in which case they should run uncapped. But I'm not
sure that would be better — it doesn't really make sense to waste
resources rendering more frames that won't be visible anyway? Opinions? 


> Window last mapped on rotated screen is not capped when unmapped.

That's not with vblank_mode=0, is it?

The difference appears to be due to radeon_dri2_drawable_crtc()
returning -1 for rotated CRTCs, so all sync to vblank functionality is
skipped for those. 

Jerome/Mario, what's the rationale for that?


-- 
Earthling Michel Dänzer           |                   http://www.amd.com
Libre software enthusiast         |          Debian, X and DRI developer