Re: Error in syslog on 2.6.20

[Tejun Heo]

William Thompson wrote:
> I'm not on either list, keep me in CC.
> 
> I noticed the following error on a cdrom device:
> ata2.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x2 frozen
> ata2.00: cmd a0/00:00:00:00:20/00:00:00:00:00/a0 tag 0 cdb 0x0 data 0
>          res 40/00:03:00:00:00/00:00:00:00:00/a0 Emask 0x4 (timeout)
> ata2: soft resetting port
> ata2.00: configured for MWDMA2
> ata2: EH complete
> 
> This is the device when it was found:
> libata version 2.00 loaded.
> ata_piix 0000:00:1f.1: version 2.00ac7
> ata1: PATA max UDMA/100 cmd 0x1F0 ctl 0x3F6 bmdma 0xFFA0 irq 14
> ata2: PATA max UDMA/100 cmd 0x170 ctl 0x376 bmdma 0xFFA8 irq 15
> scsi0 : ata_piix
> ata1.00: ATA-4, max UDMA/66, 16514064 sectors: LBA
> ata1.00: ata1: dev 0 multi count 8
> ata1.00: configured for UDMA/66
> scsi1 : ata_piix
> ata2.00: ATAPI, max MWDMA2
> ata2.00: configured for MWDMA2
> scsi 0:0:0:0: Direct-Access     ATA      WDC WD84AA       05.0 PQ: 0 ANSI: 5
> scsi 1:0:0:0: CD-ROM            LITEON   CD-ROM LTN486S   YQSM PQ: 0 ANSI: 5
> 
> I have a program that does a scsi TEST UNIT READY on many devices once every
> .1 second.  The problem occured when I ejected the cdrom and closed the tray
> again with valid media in the drive.  My program noticed media removed and
> inserted, then said the device was dead/unpollable.  This is when I saw this
> error.

Your cd rom failed to complete the TUR command your program issued in
the specified timeout.  ODDs sometimes take quite long to finish TUR or
any other command when media is changed.  Did you use sg command or
cdrom ioctl?

Anyways, after timing out, libata EH kicked the cdrom in the ass and
world peace is restored.

-- 
tejun
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/