x220 notes

[Ian Smith]

On Mon, 2 Apr 2012, ??????? ???????? wrote:
[Matt wrote:]
 > > Only the fan speed value shows as 0xFFFF or something, however it can
 > > still be set 1-7 or back to automatic as usual

Plus 0 for off, I guess?

 > Sorry for asking, but I just can't find this. What is the command for
 > changing the fan speed, especially to auto?

Snippets from the (overdone) fan control script [0] running on my T23:

sysctl dev.acpi_ibm.0.fan=0 >/dev/null  # turn auto fan control OFF
		sysctl dev.acpi_ibm.0.fan_level=$level >/dev/null
		echo "`sysctl -n dev.acpi_ibm.0.fan_speed`rpm" >>$log
sysctl dev.acpi_ibm.0.fan=1 >/dev/null  # auto fan ON

On this, the auto fan would let temperatures rise to 65C or more, then 
turn the fan full on until below about 45C, then off.  Using the half 
speed as well keeps idle temperature steady mostly between 44-48C while 
being virtually silent, and is just as responsive to load/heat peaks.

The T23 having only off, half and full speeds simplifies code though.

cheers, Ian

[0] http://smithi.id.au/temp_t23