FAILURE - WRITE_DMA timed out

[Christopher Vance]

When I use SATA disks heavily on a 5.3-R machine (Athlon) with the
SiI3512 disk controller, I get frequent (sometimes one every 1-5
minutes) WRITE_DMA timed out messages (with different blocks and both
disks).

It also panics with more than one kind of panic, and sometimes doesn't
even get to finish the background fsck from the previous panic before
dying again.

Given that both disks get the WRITE_DMA messages, and the one with the
OS on didn't have any problems when used with a VIA controller in a
different machine, I tend to think it's either the controller or the
software driving it.

Would I have any joy upgrading along 5-STABLE, perhaps after I move
the disk back to the machine that works, or won't that make any
difference?  (As in, are there any relevant ata changes since then?)

I've already tried setting both hw.ata.ata_dma and hw.ata.wc to 0, but
I still get these timeouts.

-- Frustrated in Sydney