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. > > so the ineffectiveness of this boot parameter seems to be explained. > Might there be some other syntax for this parameter? > > Nevertheless, my problem now has a work-around and I am very happy. > Thanks, Niklas. > > Kind regards, > > Jaap Berkhout -- Damien Le Moal Western Digital Research
