iwagn resets power_level to 0
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
Ubuntu |
Invalid
|
Undecided
|
Unassigned | ||
Bug Description
After upgrading to Ubuntu 9.04 Intel PRO/Wireless 4965 device would no longer stay in power save mode. My laptop is Thinkpad X61s equipped with Intel Wireless 4965 (lspcid reports 03:00.0). The right palm rest gets extremely hot when the wireless card power save mode is not engaged. In this model the wireless card is located on the right side just below the palm rest. It gets really hot very fast if the wireless card power save mode is not activated. I was using the following command to activate the power saving mode:
for i in /sys/bus/
It was working fine with 8.10, but after upgrading to 9.04 the power save mode would not stick. I see the requested power save mode reported for about 1 minute after setting the mode. It would reset to the default, no power save mode, in about 1 minute.
Here's the command I use to activate iwlagn power save mode:
for i in /sys/bus/
On the next step I would check the power state:
for i in /sys/bus/
SYSTEM:auto MODE:fixed INDEX:5
If I wait about a minute the power level gets reset to the default, no power save, INDEX:0
for i in /sys/bus/
SYSTEM:auto MODE:fixed INDEX:0
This issue makes thinkpad x61s really unpleasant to use.
I have the same problem.
Workaround: After every kernel update I must recompile the wireless driver from compat-wireless with the following modifications in iwl-4965.c
struct iwl_cfg iwl4965_agn_cfg = {
...
.broken_powersave = true
}
change this to
struct iwl_cfg iwl4965_agn_cfg = {
...
.broken_powersave = false
}
So I must set broken_powersave = false to get working wlan powsersafe.
broken_powersave = true has been introduced in the kernel as a "bug fix" to prevent some other bug (that is not interesting for me, because it is more important to keep the wlan card cool), see http:// readlist. com/lists/ vger.kernel. org/linux- kernel/ 149/746227. html