Re: Misidentification and failing revalidations of ide dvd-roms with libata

[Simen Timian Thoresen <simentt@dolphinics.no>]

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