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orschiro

Member

Registered: 2009-06-04

Posts: 2,136

Website

[solved] Cannot write to pcie_aspm - Operation not permitted

Hello,

I would like to use some powersaving settings:

[orschiro@thinkpad ~]$ cat /sys/module/pcie_aspm/parameters/policy
[default] performance powersave 

However, I cannot write the powersave setting:

[root@thinkpad orschiro]# echo powersave > /sys/module/pcie_aspm/parameters/policy
bash: echo: write error: Operation not permitted

Could somebody explain me why even root is not permitted to write to that file?

Regards

Last edited by orschiro (2012-12-17 20:33:00)

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@orschiro

WonderWoofy

Member

From: Los Gatos, CA

Registered: 2012-05-19

Posts: 8,414

Re: [solved] Cannot write to pcie_aspm - Operation not permitted

I think because this is something that is set on boot... I could be totally wrong though.  I noticed this as well.  I think though that unless it tells you that it is set to powersave, there is no need to worry, as I think that default is equivalent to powersave.

orschiro

Member

Registered: 2009-06-04

Posts: 2,136

Website

Re: [solved] Cannot write to pcie_aspm - Operation not permitted

I just found the solution. To be able to write to this file you have to use pcie_aspm=force as boot parameter.

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@orschiro