[Soekris] FreeBSD CF DMA problem

[John Murphy]

My net4801 is into its 3rd year running FreeBSD on a standard HD 24/7.
Can't expect it to last forever though.  So I'm trying to get a CF
working without much luck so far.  It's a Kingston 1GB 50x 'elite pro'

Pri Sla  CF300  (LBA Xlt 999-32-63  1007 Mbyte)
[...]
ad1: 983MB <CF300 Ver1.27> at ata0-slave UDMA33
ad1: TIMEOUT - READ_DMA retrying (1 retry left) LBA=0
ad1: TIMEOUT - READ_DMA retrying (0 retries left) LBA=0
ad1: FAILURE - READ_DMA timed out LBA=0
ad1: TIMEOUT - READ_DMA retrying (1 retry left) LBA=1
ad1: TIMEOUT - READ_DMA retrying (0 retries left) LBA=1
ad1: FAILURE - READ_DMA timed out LBA=1
ad1: TIMEOUT - READ_DMA retrying (1 retry left) LBA=0
ad1: TIMEOUT - READ_DMA retrying (0 retries left) LBA=0
ad1: FAILURE - READ_DMA timed out LBA=0

That's with hw.ata.ata_dma="0" in /boot/loader.conf
and sysctl hw.ata.ata_dma shows hw.ata.ata_dma: 0

Is there anything else I can try to force a PIO mode?

I'm still using comBIOS ver. 1.24 but I didn't see anything in
the changelog to indicate that upgrading would help.

(FreeBSD-6.0 by the way.  6.1 will be going on the CF hopefully)

-- 
John.