If I boot with kernel 5.10.20, the fan stays quiet after suspend.
If I boot with any later kernel (I’ve tried 5.11 and 5.12), the fan runs at full speed after suspend. I then have to do a cold reboot to fix the problem with the fan.
I tried Fedora, Ubuntu, Pop!_OS and Arch Linux on the X260, same experience with kernel version and fan after suspend. Ubuntu 20.04 LTS works as expected (it’s on kernel 5.8 for now), but I prefer Fedora and new shiny things.
For the time being, I’ve followed these instructions to downgrade and lock the kernel.
I hope there’s something simple I can change to make this laptop more future-proof?
$ uname -a
Linux lenovo 5.10.20-200.fc33.x86_64 #1 SMP Thu Mar 4 13:18:27 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
WIth SELinux, it is possible to manipulate different capabilities, so as listed in SELinux Wiki → Navigation: AdvancedUsers → Object Classes and Permissions descriptions it shout be possible to block system suspension with the block_suspend permission.
So, this a feature that’s available on a Fedora machine. I believe there are other solutions, but haven’t tried any solution up to that point.
I’m not exactly sure which kernel supports and checks which permissions, but I have read something that not all kernels understand that permission yet.