operation not permitted

[Karl Auer]

On Wed, 2024-03-13 at 05:31 -0400, Jerry Geis wrote:
> THanks Karl - I had found the grub command also - but was not wanting
> to reboot at the moment - was wanting to change it live.
> Might keep this for next time I reboot.
> 

If I understand that snippet correctly, the force thingy "unlocks" the
proc file so you can write to it. Could be wrong. But it's either
locked or unlocked at boot. So there's no way to escape a boot as it's
locked at the moment. IF our understanding of that snippet is correct.

BTW there is definitely something special about that proc file. Check
this out (done in a virtual 20.04, X is to avoid wrap):

root at devvm:~# cat /sys/module/pcie_aspm/parameters/policy
[default]
performance powersave powersupersave
root at devvm:~# echo "performance" > X
root at devvm:~# cat /sys/module/pcie_aspm/parameters/policy
default [performance] powersave powersupersave 
root at devvm:~# echo "default" > X
root at devvm:~# cat /sys/module/pcie_aspm/parameters/policy
[default] performance powersave powersupersave

Although I was able to modify the proc file, this is the boot command
line in the virtual:

root at devvm:~# cat /proc/cmdline 
BOOT_IMAGE=/boot/vmlinuz-5.15.0-100-generic root=UUID=86a0079e-2534-
4f9a-b137-3ccb377491a2 ro quiet splash vt.handoff=7

Nothing about "pcie_aspm=force". But it could well be different on real
hardware.

I repeat that *** I have no clue about this stuff *** :-)

Regards, K.

-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Karl Auer (kauer at biplane.com.au, he/him)
http://www.biplane.com.au/kauer