When I try to change the link power management policy of my sata controller, it does not work. What’s up with that?

Check it out:

echo min_power > /sys/class/scsi_host/host0/link_power_management_policy && cat /sys/class/scsi_host/host0/link_power_management_policy

It always stays min_power! ARGH! If I try something other than min_power, it throws an error, so I’m confused:

echo min_performance > /sys/class/scsi_host/host0/link_power_management_policy
bash: echo: write error: Invalid argument

Same thing happens on host1. I wonder what is up with this?

Based on some quick research, it seems like some hardware doesn’t support min_power, or that the drivers for them just aren’t set up right yet.

For what its worth, I was wondering what other options might apply here and found medium_power; that doesn’t work for me either.