Alan Cox wrote:
> 
> We ought to mask and copy the original yes. The number of times we've
> had Linux driver breakages by not masking and avoiding writes to
> reserved bits is small but it does happen occasionally.

That sounds reasonable. I attached a patch that should do this. 
According to what was done before (i.e. writing on the reserved bits), 
the 12 LSB of ATTBASE should be discarded...
The patch is against 2.4.19-pre8-ac5

Please test

Best regards

Nicolas.
-- 
Nicolas Aspert      Signal Processing Institute (ITS)
Swiss Federal Institute of Technology (EPFL)