Call for testers: Apple ATA DMA

[Nathan Whitehorn]

Marco Trillo wrote:
> Hi Nathan,
> 
> I tested the patch on a eMac G4 "USB 2.0" (PowerMac6,4). It has an ata-3 macio cell and a Kauai controller.
> 
> acd0: DVDR <HL-DT-ST RW/DVD GCC-4481B/2.05> at ata0-master WDMA2
> ad0: 38166MB <Seagate ST340015A 3.01> at ata1-master UDMA100
> WARNING: WITNESS option enabled, expect reduced performance.
> acd0: WARNING - SETFEATURES SET TRANSFER MODE taskqueue timeout - completing request directly
> acd0: TIMEOUT - READ_BIG retrying (1 retry left)
> acd0: WARNING - SETFEATURES SET TRANSFER MODE taskqueue timeout - completing request directly
> acd0: TIMEOUT - READ_BIG retrying (0 retries left)
> acd0: WARNING - SETFEATURES SET TRANSFER MODE taskqueue timeout - completing request directly
> acd0: FAILURE - READ_BIG timed out
>  ...
> And then the same cycle starts again.
> 
> This looks similar to the problems Marcel reported, but in this case the Kauai controller only has one device attached, the hard disk; as the CD drive is on the ata-3 macio controller instead.

Ugh. I really don't know, and am flying blind without hardware. If you 
disable ATAPI DMA or the macio controller, does ad0 at least work?
-Nathan