Re: Multiple errors with DVD drive

J.J. Berkhout
2022-09-23T12:14:23Z

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On 23-09-2022 00:08, Damien Le Moal wrote:
> On 9/21/22 21:38, J.J. Berkhout wrote:
>> Hello,
>>
>>
>>
>> On 21-09-2022 13:58, Niklas Cassel wrote:
>>> Another way do disable lpm is to do:
>>>
>>> $ ls -al /sys/class/scsi_host/host*
>>>
>>> Find your device in the list. My device is:
>>> /sys/class/scsi_host/host13/
>>>
>>> Print the current lpm policy for your device:
>>> $ cat /sys/class/scsi_host/host13/link_power_management_policy
>>> med_power_with_dipm
>>>
>>> Anything other than "max_performance" means that you have (a varying degree)
>>> of low power modes enabled.
>>>
>>> $ sudo sh -c "echo max_performance > /sys/class/scsi_host/host13/link_power_management_policy"
>>>
>>> $ cat /sys/class/scsi_host/host13/link_power_management_policy
>>> max_performance
>>>
>>> Try reading from the optical drive after ensuring that the policy is
>>> "max_performance".
>>>
>>
>> Yes, this worked and did the trick! Reading without any errors. I did
>> not yet try to write, but will do so today.
>> When booting with libata.force=nolpm the link_power_management_policy
>> was still med_power_with_dipm and I got the dmesg:
>>
>> [ 0.291452] ata: failed to parse force parameter "nolpm" (unknown value)
>
> What kernel version are you running ? This should work with the latest
> kernels. Your kernel likely pre-dates the addition of all the ata horkage
> flag as boot parameter options, which I think was with 5.18 kernel.

Yep, I run Ubuntu 5.15.0-48-generic kernel. I circumvented this by
using sysfsutils with
class/scsi_host/host0/link_power_management_policy = max_performance
in the /etc/sysfs.conf file. As long as I don't mess around with my
hardware, the host number should stay the same.

Kind regards,

Jaap Berkhout