Hi,

In my PM 9600, I have an Adaptec 2940UW and a PCI IDE controller with a
CMD Technology PCI0648 controller. Both are running at speeds other than
their default:

ahc0 at pci0 dev 13 function 0
ahc0: interrupting at irq 23
ahc0: aic7880 Wide Channel A, SCSI Id=7, 16/255 SCBs
...
sd0 at scsibus0 target 0 lun 0: <IBM, DDYS-T18350N, S96H> SCSI3 0/direct fixed
sd0: 17501 MB, 15110 cyl, 6 head, 395 sec, 512 bytes/sect x 35843670 sectors
sd0: sync (100.0ns offset 8), 16-bit (20.000MB/s) transfers, tagged queueing

I was just using a Symbios card which used ultra SCSI speed (50 ns, wide),
but I may need that elsewhere and I don't see why this Adaptec card won't
do ultra speed. This Adaptec just came out of an i386 machine running
NetBSD where it did the full 40 meg / sec.

Then, the IDE card:

pciide0 at pci1 dev 14 function 0: CMD Technology PCI0648 (rev. 0x01)
pciide0: bus-master DMA support present
pciide0: primary channel configured to native-PCI mode
pciide0: using irq 28 for native-PCI interrupt
wd0 at pciide0 channel 0 drive 0: <IC35L120AVVA07-0>
wd0: drive supports 16-sector PIO transfers, LBA addressing
wd0: 115 GB, 16383 cyl, 16 head, 63 sec, 512 bytes/sect x 241254720 sectors
wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 5 (Ultra/100)
wd0(pciide0:0:0): using PIO mode 4, Ultra-DMA mode 2 (Ultra/33) (using DMA data
transfers)

This card is supposed to be a Ultra/66 card, but it's only using Ultra/33.
I've looked at whatever documentation I could find regarding IDE flags,
but came up with nothing; the code in sys/dev/pci/pciide.c appears to
support up to mode 4, but I'm not clear about why the mode is limited.

I tried changing:
           if (drvp->UDMA_mode > 2 &&
             (pciide_pci_read(sc->sc_pc, sc->sc_tag,
             CMD_BICSR) &
             CMD_BICSR_80(chp->channel)) == 0)
               drvp->UDMA_mode = 2;
(line 2630) to:
               drvp->UDMA_mode = 4;
and got:
wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 5 (Ultra/100)
wd0(pciide0:0:0): using PIO mode 4, Ultra-DMA mode 4 (Ultra/66) (using DMA
data transfers)

But, honestly, I don't know what CMD_BICSR and friends are, so I don't
know why these tests are being performed and why UDMA_mode is being
lowered.

Initial tests (very preliminary) show that using mode 4 works fine.

Has anyone seen either of these problems? What's the best way to get
UDMA/66 - an option for the kernel config file?

Thanks,
John Klos
Sixgirls Computing Labs