Re: Misidentification and failing revalidations of ide dvd-roms withlibata

From: Simen Timian Thoresen
Date: Thu Jul 31 2008 - 00:44:21 EST


Simen Timian Thoresen wrote:
Alistair John Strachan wrote:
On Sunday 27 July 2008 20:33:21 Simen Timian Thoresen wrote:
[snip]
I've spent a few hours more looking into this, and I'm not really
getting much clearer;

I've run either and both of the two DVDroms on an external power-supply
(drive-power from a jumped, believed good ATX-PSU), and the the symptoms
remain; inconsistent capabilities reported at boot, and when I start
ripping CDs, one of them will fail as above.

As I still have the impression that this started when I switched distros
(ie went from CentOS4 2.6.9 pre-libata-kernel to the current Ubuntu 8.04
2.6.24-kernel), I've now started playing around with the libata module
parameters.

Hi Alistair,

I'm sorry I have not yet come back on this. I /think/ I've had success disabling DMA for atapi-devices (adding "options libata dma=5" to my modprobe.conf file). I've been able to rip a number of cds without any issues with this (except a reduced speed, I believe). I do get some noise in dmesg;

[ 9686.570804] end_request: I/O error, dev sr1, sector 0
[ 9686.570814] Buffer I/O error on device sr1, logical block 0
[ 9686.570819] Buffer I/O error on device sr1, logical block 1
[ 9686.572134] end_request: I/O error, dev sr1, sector 1024
[ 9686.573105] end_request: I/O error, dev sr1, sector 1024
[ 9686.574101] end_request: I/O error, dev sr1, sector 1024


...but cdparianoia (ripper application) never complains and I've not been able to notice any defects in the extracted audio.

As this was disabling DMA, and I've seen that frequency adjustments on the CPU can cause DMA issues (at the time, with the ivtv-driver) on this motherboard, I thought that I'd try disabling Cool'n'Quiet and thereby lock the CPU to full speed, while reenabling DMA, but that did not help. Ripping the first CDs, one of the drives failed again.

If it's not power then I'm still with Alan re the cables. Maybe you have very long cables?

Nope, normal 40cm'is 80-pin IDE cables. While one could be bad, I wouldn't expect both to be (etc).

I used Alan's nForce4 pata driver for a year or so and didn't have any problems. OTOH maybe at this stage it's worth checking whether amd74xx (old IDE) breaks in similar ways?

from dmesg, I have this;

[ 17.647757] pata_amd 0000:00:06.0: version 0.3.10
[ 17.650097] scsi0 : pata_amd
[ 17.650229] scsi1 : pata_amd
(that's the one, right?)

...so the driver exists in the running kernel. Would I have to build my own kernel, or is there some way to have this driver take hold instead of libata? ...or can I do something in modprobe.conf to use the other driver?

Also, I assume you've memtest86'ed the machine?

Not strictly recently. I'll leave it doing so this evening, as I'll want to reboot it to reactivate Cool'n'quiet.

It passed 22 runs over the night.

I'll aim to build a new kernel using the amd74xx pata driver over the weekend. For now, I can work with the system as it is using PIO for the DVDrom drives.

Yours,
-S

Again, thank you for helping me look into this. For now it /looks/ like I could be happy doing PIO, but I'd prefer to have this solved properly if possible.

-S



--
Simen Thoresen, Dolphin ICS
Systems Administration and Wulfkit Support
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