Description of problem:
As soon as I disable my onboard ethernet port, either by bios configuration, by software or by hardware (pulling the ethernet cable), I get SATA bus errors almost immediately. (the board is a ABIT IP35V LGA775 FSB1333 SATA)

Version-Release number of selected component (if applicable):
kernel-PAE-2.6.33.5-124.fc13.i686
also tested with kernel-PAE-2.6.32.12-115.fc12.i686 (same results)

How reproducible:
always

Steps to Reproduce:
1. do one of the following:
   a) pull ethernet cable
   b) /sbin/ifdown eth0
   c) boot with onboard NIC disabled completely in BIOS
   ie anything that turns off the onboard ethernet port LED
2. dd if=/dev/sda of=/dev/null
3. wait 10 to 20 seconds

Actual results:
for 2a and 2b, the message

Jun 26 19:45:22 helen kernel: sky2 eth0: disabling interface

is logged. After step 3, the kernel starts reporting varying bus errors

sometimes this:
Jun 26 22:32:28 helen kernel: ata3.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6
Jun 26 22:32:28 helen kernel: ata3.00: BMDMA stat 0x66
Jun 26 22:32:28 helen kernel: ata3.00: failed command: WRITE DMA
Jun 26 22:32:28 helen kernel: ata3.00: cmd ca/00:08:cd:17:78/00:00:00:00:00/e3 tag 0 dma 4096 out
Jun 26 22:32:28 helen kernel:         res 51/84:01:d4:17:78/00:00:00:00:00/e3 Emask 0x30 (host bus error)
Jun 26 22:32:28 helen kernel: ata3.00: status: { DRDY ERR }
Jun 26 22:32:28 helen kernel: ata3.00: error: { ICRC ABRT }
Jun 26 22:32:28 helen kernel: ata3: soft resetting link
Jun 26 22:32:28 helen kernel: ata3.00: configured for UDMA/133
Jun 26 22:32:28 helen kernel: ata3.01: configured for UDMA/133
Jun 26 22:32:28 helen kernel: ata3: EH complete

sometimes this:
Jun 26 19:41:16 helen kernel: ata3.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
Jun 26 19:41:16 helen kernel: ata3.00: failed command: WRITE DMA
Jun 26 19:41:16 helen kernel: ata3.00: cmd ca/00:48:05:38:08/00:00:00:00:00/e3 tag 0 dma 36864 out
Jun 26 19:41:16 helen kernel:         res 40/00:00:e5:10:34/00:00:00:00:00/e1 Emask 0x4 (timeout)
Jun 26 19:41:16 helen kernel: ata3.00: status: { DRDY }
Jun 26 19:41:21 helen kernel: ata3: link is slow to respond, please be patient (ready=0)
Jun 26 19:41:26 helen kernel: ata3: device not ready (errno=-16), forcing hardreset
Jun 26 19:41:26 helen kernel: ata3: soft resetting link
Jun 26 19:41:26 helen kernel: ata3.00: configured for UDMA/133
Jun 26 19:41:26 helen kernel: ata3.01: configured for UDMA/133
Jun 26 19:41:26 helen kernel: ata3: EH complete

Using a different disk (here /dev/sdb instead of /dev/sda) makes no difference:
Jun 26 19:45:32 helen kernel: ata3.01: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6
Jun 26 19:45:32 helen kernel: ata3.01: BMDMA stat 0x66
Jun 26 19:45:32 helen kernel: ata3.01: failed command: READ DMA
Jun 26 19:45:32 helen kernel: ata3.01: cmd c8/00:00:e0:60:01/00:00:00:00:00/f0 tag 0 dma 131072 in
Jun 26 19:45:32 helen kernel:         res 51/84:a3:3d:61:01/00:00:00:00:00/f0 Emask 0x30 (host bus error)
Jun 26 19:45:32 helen kernel: ata3.01: status: { DRDY ERR }
Jun 26 19:45:32 helen kernel: ata3.01: error: { ICRC ABRT }
Jun 26 19:45:32 helen kernel: ata3: soft resetting link
Jun 26 19:45:32 helen kernel: ata3.00: configured for UDMA/133
Jun 26 19:45:32 helen kernel: ata3.01: configured for UDMA/133
Jun 26 19:45:32 helen kernel: ata3: EH complete

The log then starts filling with these errors, about one every 10 to 20 seconds. After the "Emask 0x4 (timeout)" kind of errors, the system freezes for about 10 to 20 seconds. Sometimes, the system freezes with a message different from the ones above and does not wake up anymore (I can see this message with dmesg shortly before it freezes). Sometimes, switching console still works, sometimes, it's completely frozen.

Expected results:
Problems after step 3 do not happen.

Additional info:
- I think that this is not a hardware problem because KNOPPIX 6.2 does not have the problem.

- The dd is not actually necessary. It can be caused by any disk access (but one has to wait for one then).

- disk info:
ata3.00: ATA-7: SAMSUNG HD200HJ, KF100-06, max UDMA7
ata3.00: 390721968 sectors, multi 16: LBA48 NCQ (depth 0/32)
ata3.01: ATA-7: SAMSUNG HD103UJ, 1AA01113, max UDMA7
ata3.01: 1953525168 sectors, multi 16: LBA48 NCQ (depth 0/32)
ata3.00: configured for UDMA/133
ata3.01: configured for UDMA/133

ata3.00 = sda; ata3.01 = sdb