Pipe vs. plane fixes (hopefully third time's the charm)

[Jesse Barnes]

On Tuesday, September 11, 2007, Lukas Hejtmanek wrote:
> On Tue, Sep 11, 2007 at 03:17:05PM -0700, Jesse Barnes wrote:
> > Rather than storing the plane->pipe mapping in the SAREA, I now
> > just have the DRM figure it out from the display registers.
>
> Just a note. I do not know how often the mapping needs to be read but
> reading the register could be *much* slower than reading in memory
> structure.

We already have to read a few registers on this path though, so any 
added cost should be hard to measure...

Jesse