clopez / dellfan

User space utility to control the fan speed on Dell Laptops

dellfan - user space utility to control the fan speed on Dell Laptops.

• Allows to set the fan speed of a Dell laptop to 0 (disabled), 1 (medium) and 2 (full speed).

Caveats

• The BIOS of some newer Dell laptops (Latitude E6420/E6520/E6430/E6530/E6440/E6540/...) will override the speed you set unless you disable the BIOS control.
  • I found two methods of disabling the BIOS control:
    • By default DISABLE_BIOS_METHOD1 will be used.
    • If you want to try DISABLE_BIOS_METHOD2 edit the source code.
  • On my laptop (E6420), when you disable the BIOS control over the fan some weird things happen:
    • The Fn keys stop working.
    • Suspend to RAM sometimes stops working: The laptop will power itself off instead of suspending.
      • This happens every time on the M4600. The solution is running dellfan 0 0 before putting the machine to sleep.
• Please, if you find a new method of disabling the BIOS control, let me know it.
  • There is a function that allows to discover new codes by proving (use with care).