[ath9k-devel] need help debugging/pinning down obscure freezes/hangs using AR9287

[Ben Greear <greearb@candelatech.com>]

On 10/13/2011 09:26 AM, Philipp Raich wrote:
> On Wed, Oct 12, 2011 at 9:35 PM, Ben Greear<greearb@candelatech.com>  wrote:
>> On 10/12/2011 12:19 PM, Philipp Raich wrote:
>>>
>>> Sadly, the provided patch did not help (I applied it to to the
>>> compat-wireless tarball '2011-10-10', hopefully this was right). I did
>>> not encounter any warnings so far.
>>>
>>> I just realized, that cfg80211 is initialized with the country code
>>> for China, because thats what ath9k reads from the eeprom of my
>>> wireless card - I guess my retailer sold me a card  intended for the
>>> chinese market :S.
>>>
>>> I don't think this could be the reason for the freezes, or could it?
>>> (adding "options cfg80211 ieee80211_regdom=AT" to
>>> "/etc/modprobe.d/cfg80211.conf" did not resolve the issue).
>>
>> It might be nice to attempt a quick hack to over-ride the country
>> code to see if that helps anything.
>
> I tried to verify if the override mentioned from above effectively
> changes the setting. In fact i might get a "manual regulatory setting
> ignored because driver wants its own regulatory setting to be set
> first" (i don't know the exact wording, machine just crashed, haha).
> Other times it seems the setting is accepted, although i should see
> more channels being available with "iwlist wlan0 frequencies", and I
> do not?
> I will try to hack that setting and keep you updated if it changes
> anything. Would be strange though...?
>
> Anyway, the country code should be easier to change/fix imho, wireless
> devices are by design prone to changes of location I would say. And I
> feel ripped of by the retailer...

There are patches to support forcing the country code, but
they can allow you to mis-configure things in an illegal
manner in your particular location, so they are somewhat
frowned upon by the official wifi folks.  Used with care, it
appears to work fine.

You will probably have to hand-apply the patches, or perhaps
google around to find more recent ones:

http://forum.aircrack-ng.org/index.php?topic=6822.0

I do doubt this will really fix your problem, but it's
a relatively easy change to test.

>> Also, do you have another ath9k nic that you could use instead
>> to see if the problem happens with multiple nics and/or
>> chipsets?
>>
>> Or can you put your existing NIC into a different computer
>> and see if the problem remains?
>
> Unfortunately, no to both suggestions, not right now and I don't see
> it happening soon, unless I buy another NIC or lend me a computer of
> someone else... I moved a few months ago and got rid of all the
> needless junk ;)
> But I like the idea, I thought of it myself - it just isn't an option right now.
> The only thing i might say: In Windows the NIC works like a charm. The
> connection is considerably faster and more reliable and the OS
> obviously never crashed.

If you _could_ get a different ath9k NIC to try out (slightly different
chipset, manufacturer, etc) it should provide some good info.  If you're
in the US and would like to pay shipping have some NICs I could
send you for testing in your system.

Or, try with a different AP perhaps.  Anything to start narrowing down
the issue so that others might be able to reproduce the problem.

Also, if you are booting from windows to Linux, try completely
powering down the system between reboots.  That has helped
with strange problems in the past (nic is sometimes left in funky
state through soft boots from one OS to another).

Thanks,
Ben

>
>
> Thanks,
> Philipp


-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com