Re: 2.6.29-rc8: Reported regressions from 2.6.28

From: Johannes Berg
Date: Tue Mar 17 2009 - 17:28:26 EST


On Mon, 2009-03-16 at 21:24 +0800, Jeff Chua wrote:

> Here's what I did, and it's repeatable.
>
> Take the attached bisect log and replay it, and the last offending
> commit is this ...
> # git log
> commit 71c11fb57b924c160297ccd9e1761db598d00ac2
> Author: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
> Date: Tue Oct 28 18:29:48 2008 +0100
>
> b43/legacy: remove SSID code
>
> Yes, this is not the real problem, but it's the last commit that cause
> the problem, and I couldn't bisect further, typing the next "git
> bisect bad" and the commit is

I'm on 0191b62 now and cannot reproduce the problem with iwlwifi
hardware and a linksys (broadcom-based) AP with hidden SSID.

> Anything I can help to debug further, just let me know.

Compile iwlwifi with debugging please, and instead of plain modprobe
iwlagn, do this:
modprobe iwlagn debug=0x800 debug50=0x800

Then send me the relevant dmesg output from a working and a failed
attempt. You should see something like this

[ 318.420537] ieee80211 phy4: U iwl_bg_request_scan Start direct scan for 'myssid'

in the log. I can't see any reason why it would be missing. For me, the
association is instantaneous after saying "ap any". This is expected
too, because
iwconfig wlan0 essid "myessid"
will have triggered a directed scan for the AP.

There are two possible failure scenarios that I can imagine:

1) You see no line like the one above in your log, but rather

[ 736.047879] ieee80211 phy5: U iwl_bg_request_scan Start indirect scan.

This would indicate a bug in the driver.


2) You do see the line with the SSID, but you don't get any reply. In
this case, please try doing it manually:
iwlist wlan0 scan essid 'myssid'
Wait about 15 seconds between each attempt of doing so, and report
whether your AP is listed in the results or not. If it isn't most of the
time, then your AP is broken.

johannes

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