[PATCH] Automatically determine appropriate pipe from plane info

[Jesse Barnes]

On Tuesday, September 11, 2007, Roland Scheidegger wrote:
> On 9/12/07, Jesse Barnes <jbarnes at virtuousgeek.org> wrote:
> > Rather than keeping a copy of the plane->pipe mapping code in the
> > SAREA, just figure out what the real mapping is from the
> > DSP(A|B)CNTR register at runtime.  This should be fairly safe since
> > the DRM doesn't actually modify the pipe->plane mappings, though
> > there is the possibility for app confusion if the DDX changes the
> > mappings between a vblank swap submission and completion.
>
> Wouldn't it be simpler (if you don't want that information to be in
> the sarea) to just set the mapping with a setparam ioctl rather than
> trying to be smart and needing to figure it out every vblank?

An ioctl would have the same compatibility problem as an SAREA addition, 
since the server would have to ioctl the plane->pipe mapping info.  
This way we get forward and backward compatibility.

Jesse