Hi,

I tried the 2.6.17-rc6-mm2 kernel with PATA VIA.

The via controller still fails to set xfermode for an ATAPI drive 
plugged on a via controller (vt8235).
Now only this drive is disabled instead both device on the same port. 
But the libata core tries various speed for the failling drive and sets 
this speed also for the good device.

In my case, the ata core starts with UDMA/33, then tries UDMA/25 and 
finaly PIO0. And at the end ata4.00 is at PIO0 and ata4.01 disabled.
Why not changing only the speed of ata4.01 ?

The dmesg log is attached as dmesg_pata-mm.

I make a patch that seem to make work the drive. It is attached as 
pata-via-atapi.
I don't know if is the correct thing to do.

The dmesg log with this patch is attached as dmesg_pata-mm-f.

Matthieu