Synchronization with CRT refresh

[Michel Dänzer]

On Tue, 2005-05-03 at 14:40 -0400, Adam Jackson wrote:
> On Tuesday 03 May 2005 14:32, Michel Dänzer wrote:
> > Ahem. I implemented this in the DRM years ago. I even extended the
> > interface to optionally generate a signal instead of blocking in the
> > ioctl on request by yours truly and Keith Packard, but I'm still not
> > aware of anything using that. Oh well.
> 
> Excellent!  I anticipated needing a DRM driver for this anyway.  Is this the 
> same mechanism as handles vsync in the r200 DRM?

Yes. It's a driver-independent ioctl, i.e. the ioctl number and
interface is the same for all drivers.

One thing that's still missing is the ability to select the display
controller that should be waited for on cards with multiple controllers,
but the interface should be extensible enough that this could be added
in a backwards compatible way.


On Tue, 2005-05-03 at 14:53 -0400, Jim Gettys wrote: 
> 
> It would be good to publish the interface: we need to get the same
> interface implemented in other drivers than the DRM as well.

What would be the preferred form of publishing it? FWIW, the interface
is defined in drm.h, look for drm_wait_vblank_t.


-- 
Earthling Michel Dänzer      |     Debian (powerpc), X and DRI developer
Libre software enthusiast    |   http://svcs.affero.net/rm.php?r=daenzer