Bdtyktl

This is related to a previous question related to installation that is now resolved. I'm opening a new question, because I still need to get my DVD drive working.

Problem:

Failed boot when my ASUS DRW-24B1/ST DVD drive is attached to my asmedia ASM1061.

Symptom:

ata8.00: exception Emask 0x52 Sact 0x0 SErr 0xffffffff action 0xe frozen

ata8: SError: { blah blah }

ata8.00: failed command: IDENTIFY PACKET DEVICE

ata8.00: cmd blah blah

         res blah blah (ATA bus error)

ata8.00: status: { DRDY }

ata8: hard resetting link

Background:

The ASM1061 is a PCIe to SATA bridge providing 2 x 6Gb/s ports and is supposed to be fully compliant to SATA specs.

I just discovered in the fine print of my ASUS P8Z77-V pro motherboard that "These SATA ports are for data hard drivers only. ATAPI devices are not supported."

However, I have already installed Windows 7 using this drive and I can run the Ubuntu 12.04 installer from it as well. The only time I have a problem is during Ubuntu boot when it tries an IDENTIFY PACKET DEVICE which seems to be an ATAPI command.

I can't simply switch this device to another SATA port because they are already allocated to other devices. (My chipset's 2 x 6Gb/s are connected to my boot SSD and a fast HDD while the 4 x 3Gb/s ports are running a RAID 5 array.) If this can't be fixed or worked around, I suppose I'll have to go buy SATA add-in card. Blech.

Thoughts:

If indeed this is a device specific issue (that it doesn't support ATAPI discovery) then I can't expect - is it udev? - to work with it. But, it seems that Windows and even the Ubuntu installer work just fine. So why does udev have a problem?

At the end of the day, it would be nice to have the DVD working under Ubuntu, but I can live without it. But, as this is a dual-boot machine, I can't physically disconnect it because I want it to work with Windows. (And physically disconnecting it every time I want to boot Ubuntu is NOT an option. ;-)

Questions:

1. Should this be considered a bug? My feelings are that if it works with other OS that it should probably work with Ubuntu as well.




2. How can I work around this problem? I have a limited knowledge of linux internals, but it seems I should be able to somehow tell udev (or whatever is doing the discovery) to ignore that device. Is there a way?

Turns out these are libata messages from the kernel resulting from ATAPI commands being sent to the DVD drive. The problem is, the ASM1061 to which the DVD is attached doesn't support ATAPI.

The solution is to edit /lib/udev/rules.d/60-persistent-storage.rules, find the line containing the word "ATAPI" and comment out the next line.

Thanks to Olli Helin for his answer to my previous post for this answer!

Apparently, ASM106x and optical drives just don't go together. It works - most of the time. But then bam! the entire machine crashes, and this was the last message on screen:

ata10.00: exception Emask 0x52 SAct 0x0 SErr 0xffffffff action 0xe frozen

ata10: SError: { RecovData REcovComm UnrecovData Persist Proto HostInt PHYRdyChg PHYInt CommWake 10B8B Dispar BadCRC Handshk LinkSeq TrStaTrns UnrecFIS DevExch }

ata10.00: failed command: IDENTIFY PACKET DEVICE

ata10.00: cmd a1/00:01:00:00:00/00:00:00:00:00/0 tag 0 pio 512 in

         res 40/00:03:00:00:00/00:00:00:00:00/a0 Emask 0x56 (ATA bus error)

ata10.00: status: { DRDY }

ata10: hard resetting link

The issue also was discussed on the linux-ide mailing list: http://thread.gmane.org/gmane.linux.ide/55284

Another workaround mentioned there is libata.atapi_passthru16=0 (kernel parameter).

But in the end it seems to be a buggy SATA controller and you should avoid using it for optical drives altogether. Use a SATA port backed by another controller, or an USB adapter.