Re: sata_via: write errors on SATA drive connected to VT6421

[Robert Hancock <hancockrwd@gmail.com>]

Landry Breuil wrote:
> Hi,
> 
> i encounter a very similar problem as reported in
> http://marc.info/?l=linux-kernel&m=118764381013943&w=2, but with a SATA
> disk. Trying to transfer 250Gb (mostly small files) from a SATA disk
> (ata1/sda) to another (ata2/sdb), both plugged on the VT6421 card, after
> some dozens of seconds the controler bails out and degrades write performance
> (UDMA133->UDMA100->UDMA33...)
> 
> kernel: ata2.00: limiting speed to UDMA/33:PIO4
> kernel: ata2.00: exception Emask 0x12 SAct 0x0 SErr 0x1400500 action 0x2 frozen
> kernel: ata2: SError: { UnrecovData Proto Handshk TrStaTrns }
> kernel: ata2.00: cmd 35/00:00:07:c6:f4/00:04:07:00:00/e0 tag 0 dma 524288 out
> kernel:          res 40/00:b0:27:1d:dc/84:00:07:00:00/e0 Emask 0x16 (ATA bus error)
> kernel: ata2.00: status: { DRDY }
> kernel: ata2: port is slow to respond, please be patient (Status 0xd0)
> kernel: ata2: device not ready (errno=-16), forcing hardreset
> kernel: ata2: hard resetting link
> kernel: ata2: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
> 
> Reading big datas is okay so far. Creating a 2.5Gb file on the same disk
> with dd if=/dev/zero is okay too. dd'ing a 500Mb file 10 times in a loop
> from sda to sdb works too.

This seems to indicate that the controller lost communication with the 
drive. This is usually due to some kind of hardware problem, like a 
power issue, cable or drive problem. Given that it's occurring when both 
drives are active, a power issue is quite possible..