Linux – Ubuntu/Toshiba Fan Speed Issue

fanlaptoplinuxUbuntuubuntu 11.10

I am using Ubuntu 11.10 AMD64 on my Toshiba laptop (L505D-S5965). After I boot into the OS, my fan works perfectly being mostly quiet. Recently, I noticed that whenever I resume from system suspension, my fan starts to become noisy. This happens consistently without any programs or processes running at all. It will keep being noisy until I reboot my computer, then it goes back to normal. When the fan is noisy, the CPU temperature is 53°C, which is not hot at all. I've tried booting with pcie_aspm=force in the GRUB options file, but that did not work. Is there a fix?

Best Answer

This is a known bug in Ubuntu, dating back to 2006 :
Bug #77370 : Laptop Fan always on after resume from suspend to RAM.

The above is a very long thread going on for 6 years, concluding that this problem happens on some kernel versions, but not on all.

Some solutions were listed, going from unplug/replug the power cord to creating a script to run after resume to stop the fan.

The script in question is created as file /etc/pm/sleep.d/99fancontrol (remember to chmod 755) :

#!/bin/sh
#
# Stop the fan.
# Source: https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.17/+bug/77370

case "$1" in
 hibernate|suspend)
  # Stopping is not required.
  ;;
 thaw|resume)
# In background.
   ( sleep 10 ; echo -n "0" > /sys/devices/virtual/thermal/cooling_device1/cur_state ) &

  ;;
 *) exit $NA
  ;;
esac
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