Re: 2.6.38-rc7, iwlagn warning

[Mathias BurÃn]

On 8 March 2011 15:17, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote:
> FWIW, I'm changing the subject since "crash" bothers me, it's not even
> close to a crash.

Of course, sorry.

> On Sat, 2011-03-05 at 23:45 +0000, Mathias BurÃn wrote:
>
>> I got it again, with the newly compiled kernel. However, I've been
>> trying for 20 minutes now and when I load iwlagn with the debug
>> parameter I can't seem to get the warning. I was monitoring dmesg with
>> "watch --interval=1 "dmesg|tail -n40"" but I never saw the warning. As
>> soon as I removed the module, and inserted it again without the debug
>> option I could reproduce the warning. Here are some dmesg logs:
>
> Curious.
>
>> no debug, crash 1: http://www.privatepaste.com/download/06539404a8
>> no debug, crash 2: http://www.privatepaste.com/download/a6be5f5c81
>
> And I'd prefer if you also stopped using the word crash. Nothing
> crashed. All you got was a stack trace because I put a warning there.
> Really, not the end of the world, and in fact it probably has very
> little or even no effect on functionality.
>

Got it.

> However ... actually looking at the log files I'm totally confused what
> it is that you're doing. Something appears to be continually switching
> between interface modes, even using wireless extensions, yet it really
> wants to be IBSS all the time. What's causing all this pointless
> switching? It'd be useful to figure that out, but I'm not sure how. What
> applications are you running that manage wireless? Are you, by any
> chance, running wpa_supplicant manually in addition to network-manager?

I'm using NetworkManager, I haven't started anything else manually. I
don't know why it switches modes like that, it happens on 2 laptops
(both Ubuntu 10.10) so it could very well be some NetworkManager
related issue.

> Irregardless of that though, there's clearly some kind of bug in the
> driver since the TX power setting times out, and then as a result we get
> the warning.
>
> Would you be willing to enable tracing and capture a trace using
> trace-cmd, by running 'trace-cmd record -e mac80211 -e iwlwifi'?
>
> johannes
>
>

I've since upgraded to 2.6.38-rc8 (same config). Looking around in the
config, is it CONFIG_FUNCTION_TRACER I need to enable, and is that it?
(kernel function tracer)

// Mathias
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