Manually setting timings on PDC20269

Hi,

Is there any way to manually set the UDMA timings used to interface with a drive?

I can see in the PDC20269 driver that it is responsible for setting the timings, but I'm not sure how to adjust them at runtime. My UDMA-2 drive reverts to PIO after trying a write. Oddly, I can read from the drive using UDMA, it just times out and reverts to PIO when I try to write anything to it.

This is with kernel 2.6.0-test3...

Thanks,

Wes