Netra X1 IDE controller/disk issues

[Chris Ross <cross+netbsd%distal.com@localhost>]

  After replacing the primary internal disk on my Netra X1, it's  
running 5.1_RC1 stably.  I've since added another disk to it, a  
Samsung SP2514N (ATA/133 250GB).  The first time after I boot, I can  
label that disk, and when I try to newfs it: (partition a is all of  
the disk except the first cylinder) with the following:

# newfs -i $[32*1024] -O 2 /dev/rwd1a

  It causes the kernel to get "lost interrupt" issues, eventually  
downgrading it to PIO.  I see the following on the console [before  
newfs even begins to print the status dots]:

aceride0:1:0: lost interrupt
        type: ata tc_bcount: 512 tc_skip: 0
aceride0:1:0: bus-master DMA error: missing interrupt, status=0x21
wd1: transfer error, downgrading to Ultra-DMA mode 3
wd1a: DMA error writing fsbn 488396159 (wd1 bn 488397167; cn 484520 tn  
15 sn 62), retrying
aceride0:1:0: lost interrupt
        type: ata tc_bcount: 512 tc_skip: 0
aceride0:1:0: bus-master DMA error: missing interrupt, status=0x21
wd1: transfer error, downgrading to Ultra-DMA mode 2
wd1a: DMA error writing fsbn 488396159 (wd1 bn 488397167; cn 484520 tn  
15 sn 62), retrying
aceride0:1:0: lost interrupt
        type: ata tc_bcount: 512 tc_skip: 0
aceride0:1:0: bus-master DMA error: missing interrupt, status=0x21
wd1: transfer error, downgrading to Ultra-DMA mode 1
wd1a: DMA error writing fsbn 488396159 (wd1 bn 488397167; cn 484520 tn  
15 sn 62), retrying
aceride0:1:0: lost interrupt
        type: ata tc_bcount: 512 tc_skip: 0
aceride0:1:0: bus-master DMA error: missing interrupt, status=0x21
wd1: transfer error, downgrading to PIO mode 4
wd1a: DMA error writing fsbn 488396159 (wd1 bn 488397167; cn 484520 tn  
15 sn 62), retrying
wd1: soft error (corrected)


  After this point, it seems to work just fine, albeit I'm sure more  
slowly.

  Does anyone have any idea what might be causing this?  Assuming  
this isn't a bad drive, is there some sort of issue that might be  
happening with the second channel of the IDE controller?  Maybe an  
LBA48 issue?

  The primary disk seems to work just fine.  The disks attach at boot  
as:

aceride0 at pci0 dev 13 function 0
aceride0: Acer Labs M5229 UDMA IDE Controller (rev. 0xc3)
aceride0: bus-master DMA support present
aceride0: primary channel configured to native-PCI mode
aceride0: using ivec 180c for native-PCI interrupt
[...]
wd0 at atabus0 drive 0: <MAXTOR 6L080L4>
wd0: drive supports 16-sector PIO transfers, LBA addressing
wd0: 76344 MB, 155112 cyl, 16 head, 63 sec, 512 bytes/sect x 156353536  
sectors
wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 6 (Ultra/133)
wd0(aceride0:0:0): using PIO mode 4, Ultra-DMA mode 4 (Ultra/66)  
(using DMA)
wd1 at atabus1 drive 0: <SAMSUNG SP2514N>
wd1: drive supports 16-sector PIO transfers, LBA48 addressing
wd1: 232 GB, 484521 cyl, 16 head, 63 sec, 512 bytes/sect x 488397168  
sectors
wd1: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 5 (Ultra/100)
wd1(aceride0:1:0): using PIO mode 4, Ultra-DMA mode 4 (Ultra/66)  
(using DMA)


  Thanks.  If anyone has any ideas, I'd be happy to try something  
else to diagnose the issue.

                 - Chris