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KMK_ECS
April 21st, 2009, 01:09 PM
Hi,

After apgrading my Thinkpad T61 to Jaunty the idle power consumption increased by nearly 1 watt :(. The cause is the Intel WiFi adapter 4865AGN. In Intrepid I could switch the adapter to power saving mode with the follwoing command:


echo 5 > /sys/bus/pci/drivers/iwlagn/*/power_level

After this command the idle power consumption with lowest display brightness was 12.5 watt (1400x1050 nvidia graphic). Turning wireless lan off did not change that.

Unfortunately, changing the power level does not work with Jaunty. Although the above command initially changes the power level to 5 and reduces power consumption...


kmk@t61:~$ sudo cat /sys/bus/pci/drivers/iwlagn/0000\:03\:00.0/power_level
SYSTEM:auto MODE:fixed INDEX:5

... it switches back to level 0 shortly afterwards:


kmk@t61:~$ sudo cat /sys/bus/pci/drivers/iwlagn/0000\:03\:00.0/power_level
SYSTEM:auto MODE:fixed INDEX:0

I would greatly appreciate if someone could let me know whether there is a way to change the power level in Jaunty permanently.

Many thanks and best wishes

Karl Martin

cyprusxr3
April 28th, 2009, 06:21 PM
I seem to be having the same problem, again with the 4865agn. So... bump :)

KMK_ECS
May 17th, 2009, 11:16 PM
Hi,

I have reported this bug at Launchpad. If you also experience this problem could you please let them know here:

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/377484

Many thanks and best wishes

Karl Martin

KMK_ECS
May 24th, 2009, 04:50 AM
Apparently, it is possible to use iwconfig again in Jaunty to activate the power saving mode of the iwl4965:


sudo iwconfig wlan0 power on

This command permanently changes the power level to 3:


kmk@t61:~$ sudo cat /sys/bus/pci/drivers/iwlagn/0000\:03\:00.0/power_level
SYSTEM:auto MODE:fixed INDEX:3

However, I have not yet found a way to change the power level to 5 even though idle power consumption is now back to 12.5 watts.

Best wishes

Karl Martin