Comment 81 for bug 971061

I am afraid Windows does much more than simply polling the status of the AC adapter (which I can confirm is correctly detected by linux as well).
Let me add the following information: the files

/sys/devices/system/cpu/cpu*/cpufreq/bios_limit

should reflect the AC plug status according to the bios settings. The contents of these files cannot be modified by the user. In my case, they are not modified when plugging/unplugging the AC adapter unless I suspend/resume the machine. This means that if I boot/resume while on-battery and after a while plug the AC cable, then my cpu's are not allowed to run at maximum speed until I suspend/reboot my machine...

I think that one of the main sources of trouble is that plugging/unplugging the AC cable does not produce an ACPI event. This is something related to the BIOS and I think that Samsung should get involved into this discussion (I do not know how...).