radeon memory map & DRM patch

[Benjamin Herrenschmidt]

> Well I already looked at it and thought it's impossible this happens 
> ;-). Just for completeness, I tested with the drm patches too which 
> didn't change anything.

Unless I missed something in my tests... RADEONDRIRefreshArea() is never
called. I verified that ShadowFBInit() does succeed though (returns
TRUE). I though about a possible ordering issue with ShadowFBInit() and
thus moved the call to RADEONDRIFinishScreen to much later in
RADEONScreenInit() but the problem is the same. I'll try to trace
through the ShadowFB code but we are deep into realms of the server
where I have very little understanding...

Ben.