Re: iwl3945 delayed scan results after resume

["Dan Nicholson" <dbn lists gmail com>]

On Mon, Aug 25, 2008 at 6:01 PM, Dan Nicholson <dbn lists gmail com> wrote:
> After resuming, NM has an empty list of networks for about 30 seconds
> before the scan results are populated and it reconnects to my AP. This
> is on Fedora 9 with:
>
> NetworkManager-0.7.0-0.9.4.svn3675.fc9.i386
> NetworkManager-gnome-0.7.0-0.9.4.svn3675.fc9.i386
> kernel-2.6.25.14-108.fc9.i686
> wpa_supplicant-0.6.3-6.fc9.i386
> libnl-1.1-3.fc9.i386
>
> $ cat /sys/module/iwl3945/version
> 1.2.26kds
>
> Doing some manual testing without NM, I find that if I run iwlist
> immediately after bringing up the device, I get no results. But, if I
> sleep for about half a second after bringing the device up, I get
> results including my AP. So,
>
> # ifconfig wlan0 up && iwlist wlan0 scan
> Shows no results
>
> # ifconfig wlan0 up && sleep 1 && iwlist wlan0 scan
> Gets results
>
> Any chance this is connected to the delay with NM after resume? Is
> there anything I can do to test further? I'd be willing to build a
> wireless-testing kernel or something if this seems to be a driver
> issue.

So, the above is apparently not the problem since I can switch the
driver to disable_hw_scan=1 and get scan results immediately after
bringing the device up. Instead, this seems like it's an issue with
wpa_supplicant taking a while to start associating with the AP again.
If I'm connected to an unencrypted AP, NM reconnects immediately after
resuming.

Is this is an issue in wpa_supplicant? Or is NM waiting too long to
tell wpa_supplicant to do something? If I watch the wpa log, it prints
that there are scan results available for a while before it tries to
reauth with the AP. Any ideas? I don't really understand how NM and
wpa_supplicant interact.

--
Dan