The attached patch adds MTRR support to atyfb.

Write-combining is enabled for the whole PCI resource and an uncachable 
hole is made for MMIO registers if necessary.

I also changed aty_init() to return 0 on success like the other functions.

-- 
Ville Syrjälä
syrjala@sci.fi
http://www.sci.fi/~syrjala/