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Subject: Re: [linuxwifi] Intel Centrino Ultimate N 6300 regression
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Date:   Thu, 22 Aug 2019 23:42:16 +0100
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I was investigating what appears to be the same issue on my T420 
Thinkpad and at least found a workaround (and perhaps a clue for where 
the bug could lie).

On 22/08/2019 01:12, Nigel Sollars wrote:
> Interesting to be sure,  so here are the versions of kernel and wpa_supplicant,
> 
> 5.2.9-200.fc30.x86_64
> wpa_supplicant-2.8-2.fc30.x86_64

Are you using NetworkManager by chance? I stumbled across a Red Hat bug 
report[0] involving 'CTRL-EVENT-SCAN-FAILED ret=-22' and the proprietary 
broadcom driver. A comment there[1] describes a workaround for their 
issue, by making NetworkManager not randomise the MAC address during 
access point scans.

Adopting that workaround also works for my Centrino Ultimate-N 6300 (rev 
3e). Create a config file /etc/NetworkManager/conf.d/iwl.conf with contents:

[device]
match-device=driver:iwlwifi
wifi.scan-rand-mac-address=no

Then restart NetworkManager. Alternatively, downgrading wpa_supplicant 
(to 2.7-r3 on Gentoo ~amd64) also works for me.

- Antanas

[0] https://bugzilla.redhat.com/show_bug.cgi?id=1703745
[1] https://bugzilla.redhat.com/show_bug.cgi?id=1703745#c56