Re: [REGRESSION] libata: SATA LPM forcibly disabled on Intel Raptor Lake since Linux 6.14.

[Niklas Cassel <cassel@kernel.org>]

On Tue, Jan 06, 2026 at 08:57:07PM +0100, wolf@yoxt.cc wrote:
> Hello,
> 
> I am reporting a power-management regression in libata affecting the Intel
> Raptor Lake SATA AHCI Controller, introduced after Linux 6.14.

(snip)

> and 4 apparent dummy ports might be unexpected?
> 
> Manually setting LPM on the affected hosts fails with:
> echo med_power_with_dipm >
> /sys/class/scsi_host/host*/link_power_management_policy
> -bash: echo: write error: Operation not supported

This is most likely because your ports are marked as External / Hotplug
capable by BIOS.

LPM and Hotplug are mutually exlusive in SATA.
So in order allow your ports to detect a hotplug event, LPM cannot be
disabled.


Things you can do:
-Go into your BIOS settings and disable the hot-plugging capability for the
 ports.
-If you don't have such a setting, you can use the mask_port_ext AHCI module
 parameter. Simply add:
 ahci.mask_port_ext=<your portmask here> to your kernel command line


For more info, see this thread:
https://lore.kernel.org/linux-ide/5a74106a-d9db-4e63-b3e6-3857f30a1190@interia.pl/T/


Kind regards,
Niklas