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From: Pedro Francisco <pedrogfrancisco@gmail.com>
Date: Tue, 29 Nov 2011 15:43:27 +0000
Message-ID: <CAJZjf_xcxrQBG3zspdirqUmX5kWb+2xw4c2SJs28oKt=G=412g@mail.gmail.com> (sfid-20111129_164352_591564_B4B00669)
Subject: Re: iwl3945 firmware errors: tentative debugging
To: linux-wireless@vger.kernel.org
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Sender: linux-wireless-owner@vger.kernel.org

I'd just like to add that if I only use 802.11b-g frequencies there is
no crash on the microcode.

I'll try messing with the frequencies first before trying kernel
2.6.32 or earlier.

Now to hack that loveable /lib/crda/regulatory.bin binary file to try
every possible frequency combination....


On Thu, Nov 24, 2011 at 12:54 PM, Stanislaw Gruszka <sgruszka@redhat.com> wrote:
>
> Hi Pedro
>
> On Thu, Nov 24, 2011 at 11:49:30AM +0000, Pedro Francisco wrote:
> > iwl3945 has had firmware errors triggered 'by' NM after started using
> > nl80211 instead of wext.?Since Intel has stopped supporting iwl3945,
> > no firmware fix has been possible.?It has been workarounded by
> > disable_hw_scan=1 as default, with the penalty of network performance
> > being lower and frequent 'hangs' on the connection.
> Eh, we changed to software scan by default for workaround various
> problems. Unfortunately that is causing other problems for other
> users. For now, do not exist best default disable_hw_scan= value, that
> would pleased everyone :-(
>
> > I was able to trigger the firmware error by doing "iw dev wlan0 scan
> > passive". By comparison, "iw dev wlan0 scan"?does NOT trigger the
> > firmware error.
>
> > Having activated firmware debugging, it would seem a?firmware error
> > occurs when a full passive scan is done. If all channels 1-140 are
> > scanned passively, a firmware error occurs. If at least one of those
> > channels is actively scanned, no error occurs.
> >
> > Where should I look next?
> Good finding, I'm able to reproduce that firmware error too. Perhaps
> you could install older kernel ie. 2.6.32 or even 2.6.24 and see if you
> can recreate problem there (but I'm not sure if on older kernel
> "iw dev wlan0 scan passive" command will work). If you will find kernel
> version, where issue is not present, you might figure out what is
> different regarding setting up SCAN command, or let me know so I
> will look at that :-) If that is broken also on old kernels, we
> perhaps could modify code that will disallow to do all passive
> channels scan.
>
> Thanks
> Stanislaw