Re: [PATCH v2] Revert "cfg80211: fix processing world regdomain when non modular"

From: "Hodaszi, Robert" <Robert.Hodaszi@digi.com>
To: Johannes Berg <johannes@sipsolutions.net>
Cc: "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
Subject: Re: [PATCH v2] Revert "cfg80211: fix processing world regdomain when non modular"
Date: Fri, 14 Jun 2019 14:06:31 +0000	[thread overview]
Message-ID: <d31d9fa0-302d-8bf9-4e37-52b213583003@digi.com> (raw)
In-Reply-To: <6a9c7642a2fcca60658036c605438ff2ac982bd0.camel@sipsolutions.net>


*From:* Johannes Berg <johannes@sipsolutions.net>
*Sent:* Friday, June 14, 2019 4:01PM
*To:* Hodaszi, Robert <Robert.Hodaszi@digi.com>
*Cc:* Linux-wireless <linux-wireless@vger.kernel.org>
*Subject:* Re: [PATCH v2] Revert "cfg80211: fix processing world 
regdomain when non modular"

> On Fri, 2019-06-14 at 13:58 +0000, Hodaszi, Robert wrote:
>> I didn't just resend that. I just realized, accidentally I forgot to fix
>> the debug message printing function, that define doesn't exist anymore.
>> Sorry for the confusion!
> Oops. I looked too superficially then and didn't even see the
> difference, sorry.
>
> I guess that's why Kalle always says you should have a patch changelog
> :-)
Shame on me, I was able to make a bug in a one-line change. :)
>
>> Under "original issue", you mean the issue, which commit
>> 96cce12ff6e0bc9d9fcb2235e08b7fc150f96fd2 (cfg80211: fix processing world
>> regdomain when non modular) supposed to fix?
> Yes.
>
>> That still won't work, but
>> that didn't work neither before I reverted the patch, because crda call
>> timeout will just drop the last packet. Also, as it re-processed the
>> last request, not just resent it, it caused undesired states. Like when
>> I used 2 WiFi modules with US regulatory domains, after enumeration, my
>> global regulator domain was set to "Country 98".
>>
>> To fix my issue, why I reverted the patch, and also fix the issue the
>> reverted commit supposed to fix, I could imagine something like this.
>> But I'm not sure, it doesn't have any side effect:
> [snip]
>
> Ok, thanks. I guess I'll have to look at this in more detail.
>
> You don't happen to have a way to reproduce either issue with a hwsim
> test case?
>
> johannes
>
To tell the truth, I never tried hwsim. But it's pretty trivial to repro 
it. You just need 2 WiFi modules, and put e.g. a "sleep 1" into the udev 
or mdev script, before it would call the "crda". That should trigger the 
issue immediately. After that change, I just did an "rmmod ath10k_pci; 
modprobe ath10k_pci", and bumm, "iw reg get" will should "Country 98".

Robert