IDE on Cobalt Qube2

[Jason Thorpe <thorpej%me.com@localhost>]

I recently got a Qube2 set up and noticed extremely high CPU usage (system+interrupt time) when checking out a pkgsrc tree.  This is something that *should* be I/O bound (even with the SATA SSD I'm using).

Then I noticed this:

[     1.000000] viaide0 at pci0 dev 9 function 1
[     1.000000] viaide0: VIA Technologies VT82C586 (Apollo VP) ATA33 controller
[     1.000000] viaide0: bus-master DMA support present, but unused (couldn't map registers)
[     1.000000] viaide0: primary channel configured to compatibility mode
[     1.000000] viaide0: primary channel interrupting at irq 14
[     1.000000] atabus0 at viaide0 channel 0
[     1.000000] viaide0: secondary channel configured to compatibility mode
[     1.000000] viaide0: secondary channel interrupting at irq 15
[     1.000000] atabus1 at viaide0 channel 1
.
.
.
[     4.119931] wd0 at atabus0 drive 0
[     4.130910] wd0: <Mercury Electra 3G SSD>
[     4.130910] wd0: drive supports 1-sector PIO transfers, LBA48 addressing
[     4.130910] wd0: 111 GB, 232581 cyl, 16 head, 63 sec, 512 bytes/sect x 234441648 sectors
[     4.149946] wd0: 32-bit data port
[     4.149946] wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 6 (Ultra/133)
[     4.149946] wd0(viaide0:0:0): using PIO mode 4

Does anyone else's Qube2 get stuck using PIO mode for the disk?

-- thorpej