iwagn resets power_level to 0

Bug #367121 reported by abthere on 2009-04-26
16
This bug affects 3 people
Affects Status Importance Assigned to Milestone
Ubuntu
Undecided
Unassigned
Nominated for Karmic by Oliver
Nominated for Lucid by Oliver

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/pci/devices/*/power_level ; do echo 5 > $i ; done
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/pci/devices/*/power_level ; do echo 5 > $i ; done
On the next step I would check the power state:
 for i in /sys/bus/pci/devices/*/power_level ; do echo 5 > $i ; done
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/pci/devices/*/power_level ; do cat $i ; done
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

Fabio Marconi (fabiomarconi) wrote :

Can you please attach these files:

/var/log/syslog
/var/log/dmesg
/var/log/kern.log

in order to confirm this bug ?

Thanks in advance.

:)Fabio

Changed in ubuntu:
status: New → Incomplete
Fabio Marconi (fabiomarconi) wrote :

 Thank you for taking the time to report this bug and helping to make Ubuntu better. This bug did not have a package associated with it, which is important for ensuring that it gets looked at by the proper developers. You can learn more about finding the right package at https://wiki.ubuntu.com/Bugs/FindRightPackage .

When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://help.ubuntu.com/community/ReportingBugs.

Fabio Marconi (fabiomarconi) wrote :

We'd like to figure out what's causing this bug for you, but we haven't heard back from you in a while. Could you please provide the requested information? Thanks!

Fabio Marconi (fabiomarconi) wrote :

We are closing this bug report because it lacks the information we need to investigate the problem, as described in the previous comments. Please reopen it if you can give us the missing information, and don't hesitate to submit bug reports in the future. To reopen the bug report you can click on the current status, under the Status column, and change the Status back to "New". Thanks again!

Changed in ubuntu:
status: Incomplete → Invalid
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