Promise PDC20276 broken in 2.5 and 2.4.21-preX, but not 2.4.20

There have been two prior reports of a problem with the promise PDC20276 chipset (on-board piece-o-crap pseudo raid on some KT333 [and others?] motherboards). Both of them reported the same problem, i.e. load the pdc202xx_new driver and get "neither IDE port enabled (BIOS)" message, and therefore an inability to use drives on that controller using either the direct ide interface or the pdcraid module. This problem was reported on both kernels 2.4.21-pre1 and 2.5.46, and was reported to work correctly with 2.4.20 and 2.5.34.

Neither person got a response (at least on the list), so I can't tell if anybody is aware of this.

I'm guessing that the 2.5 problem was introduced here http://linux.bkbits.net:8080/linux-2.5/diffs/drivers/ide/pci/[email protected]

and the corresponding 2.4 backport
http://linux.bkbits.net:8080/linux-2.4/[email protected]?nav=index.html|tags|[email protected]

I've run into the same problem with 2.4.21-pre3-ac4, and can also verify that it works fine with 2.4.20.

Any takers on why the 20276 isn't getting initialized correctly anymore? Presumably this is not a problem with most of the other promise chipsets or it would be much more heavily noticed by now.

-Tupshin