Comment 17 for bug 263160

I am seeing a very similar issue with a Via VT6421 SATA Controller (non-RAID BIOS).
Jaunty with Kernel: 2.6.28-11-server on 32-bit i386 (Pentium 4)
I have two disks: WDC WD3200AAJS-00L7A0 configured in RAID 1 using 'md' software RAID.
Linear operations, like rebuilding the RAID Mirror work like a dream with no errors, but random access causes lots of errors like above (*both* drives give lots of errors). The easiest way to reproduce is simply to apt-get install a package, even for just a few megs of data, the disks go nuts.

This is brand new hardware, new hba, new disks, new SATA cards. I've tried two different PSUs and refuse to believe that this is a power issue when a brand new 280W PSU has only the Pentium 4 Motherboard and the two disks attached. Maye the Via driver has adopted the broken code from the Marvel driver and needs fixing too?

Sure enough - If I disable the write cache on the disks, the problem is gone. As it happens I want the write cache disabled anyway but this was very concerning when I first installed the box.

Example of Errors:
-------------------------
[316730.629755] ata4.00: exception Emask 0x12 SAct 0x0 SErr 0x1000500 action 0x6
[316730.629793] ata4.00: BMDMA stat 0x5
[316730.629820] ata4: SError: { UnrecovData Proto TrStaTrns }
[316730.629853] ata4.00: cmd c8/00:18:af:f1:51/00:00:00:00:00/e0 tag 0 dma 12288 in
[316730.629855] res 51/84:07:c0:f1:51/84:01:00:00:00/e0 Emask 0x12 (ATA bus error)
[316730.629948] ata4.00: status: { DRDY ERR }
[316730.629974] ata4.00: error: { ICRC ABRT }
[316730.630021] ata4: hard resetting link
[316730.980054] ata4: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
[316731.040809] ata4.00: configured for UDMA/33
[316731.040825] ata4: EH complete
[316731.045995] sd 3:0:0:0: [sdb] 625142448 512-byte hardware sectors: (320 GB/298 GiB)
[316731.046472] sd 3:0:0:0: [sdb] Write Protect is off
[316731.046475] sd 3:0:0:0: [sdb] Mode Sense: 00 3a 00 00
[316731.046649] sd 3:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[316762.000273] ata3.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
[316762.000315] ata3.00: cmd c8/00:20:2f:f3:51/00:00:00:00:00/e0 tag 0 dma 16384 in
[316762.000317] res 40/00:00:56:f1:51/00:00:00:00:00/e0 Emask 0x4 (timeout)
[316762.000409] ata3.00: status: { DRDY }
[316762.000442] ata3: hard resetting link
[316762.350049] ata3: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
[316762.390408] ata3.00: configured for UDMA/133
[316762.390422] ata3: EH complete
[316762.412082] sd 2:0:0:0: [sda] 625142448 512-byte hardware sectors: (320 GB/298 GiB)
[316762.412267] sd 2:0:0:0: [sda] Write Protect is off
[316762.412271] sd 2:0:0:0: [sda] Mode Sense: 00 3a 00 00
[316762.438540] sd 2:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA