Fedora Rawhide Flips On New SATA Power Management Policy

If you are running Fedora Rawhide (their daily/development packages) and using an Intel mobile chipset, be forewarned that they are enabling the SATA link power change that runs the slight risk of potentially causing disk corruption.

While Fedora Rawhide has improved in quality and robustness the past few years, you really shouldn't be running it on any production systems. But if you are, it may be a wise idea to do a data backup before applying the latest Rawhide kernel build.

Red Hat's Hans de Goede has went ahead and enabled the new med_power_with_dipm SATA link power management policy by default when running on Intel mobile chipsets, including laptops, NUCs, and other mini PCs relying upon the mobile processors.

This is referring to the addition in Linux 4.15 that may help save power: about 1~1.5 Watts with the med_power_with_dipm policy applied for Intel Haswell laptops and newer.

The risk of any data corruption should be minimal compared to the riskier min_power policy that previously was tested. This new "medium" policy matches the behavior of the Windows settings, so should be safer.

This Rawhide kernel change is part of a broader effort of trying to improve Linux laptop battery life with Fedora 28.

Details on the Rawhide kernel change via the devel list.