[RFC] dri2: Expose API for drivers to set drawable swap limit.

[Pauli Nieminen]

On 14/07/10 17:37 +0200, ext Jesse Barnes wrote:
> On Wed, 14 Jul 2010 16:20:40 +0300
> Pauli Nieminen <ext-pauli.nieminen at nokia.com> wrote:
> 
> > This allows ddx to set swap_limit if there is variable number of
> > buffers for drawable.
> > 
> > This allows ddx driver to select triple buffering to avoid problems if
> > frame rate is close to VSYNC rate. While driver may want to keep
> > composite swaps double buffered to save memory.
> > 
> > Signed-off-by: Pauli Nieminen <ext-pauli.nieminen at nokia.com>
> > ---
> 
> Have you tested this?  I think there are a few things on the server
> side that need work to make triple (or more) buffering work.  Here's
> the patch I last used to work on it...
> 
> To make things fast, you'll need some extra buffers allocated in the
> DRI2 drawable, and you'll need to switch between them at swapbuffers
> time, along with upping the swap_limit.
> 
> -- 
> Jesse Barnes, Intel Open Source Technology Center

Yes. It works. DDX is allocating 3 buffers behind DRI2.

ScheduleSwap does all the dirty work and rotates backing buffers for DRI2
buffers.

Pauli