2008-11-01 22:35:05

by Bernhard Schmidt

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Subject: Forcing/Forbidding specific band on iwlagn

Hello,

I have a rather user-side question, I don't know exactly whether I'm
right in here :-)

I have a Dell Latitude D630 with an Intel IWL4965AGN wireless card
running Ubuntu 8.10 amd64 (Linux 2.6.27 -> iwlagn). It is pretty flaky
and crashes my system at least once a day (when something happens with
my wireless), but that will be the subject of another debugging session.

I'm usually operating in the environment of my university where about
90% of our access points are Colubris MAP-320 (11g only), 5% are
Colubris MAP-330 (11a+11g dualradio) and 5% are Colubris MAP-625
(11a/n+11g dualradio). Unfortunately, even when sitting pretty close to
a MAP-625 my system usually connects to the 11g radio (probably because
of the slightly better RF distribution of 2.4GHz). I'm not even exactly
sure what's selecting the channel, I guess wpa_supplicant?

Are there any ways to force the card to 5GHz only (or even 11n only) for
scanning and connection purpose? I think my old Atheros-based dualband
card provided a knob for this using iwpriv, but I couldn't find anything
for iwlagn and I would have expected something more general.

Thanks,
Bernhard



2008-11-01 23:18:57

by Marcel Holtmann

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Subject: Re: Forcing/Forbidding specific band on iwlagn

Hi Bernhard,

> I have a rather user-side question, I don't know exactly whether I'm
> right in here :-)
>
> I have a Dell Latitude D630 with an Intel IWL4965AGN wireless card
> running Ubuntu 8.10 amd64 (Linux 2.6.27 -> iwlagn). It is pretty flaky
> and crashes my system at least once a day (when something happens with
> my wireless), but that will be the subject of another debugging
> session.

that is highly like due to the iwl_tx_cmd_complete BUG_ON. Newer
kernels changed it to a WARN_ON, but it is still not solved why this
happens.

Regards

Marcel