Using wpa_supplicant.conf with removable WiFi modules?

John Ernberg john.ernberg
Mon May 18 23:45:56 PDT 2015

On 2015-05-19 08:29, Peer, Ilan wrote:
> Hi,
>> -----Original Message-----
>> From: hostap-bounces at [mailto:hostap-
>> bounces at] On Behalf Of John Ernberg
>> Sent: Tuesday, May 19, 2015 09:10
>> To: hostap at
>> Subject: Using wpa_supplicant.conf with removable WiFi modules?
>> Hi
>> We're trying to use wpa_supplicant 2.4 with our removable WiFi module for
>> P2P connections. It requires some device specific settings that we specified in
>> the .conf file. The problem is that due to how configurations are assigned to
> Can you clarify this statement? What's the problem in here?
>> interfaces, we have to restart wpa_supplicant every time we re-insert the
>> module. This is not preferable to us.
> Not sure that this is the case, but is it possible that when you are removing your module cfg80211.ko is unloaded? If this is the case, then you need to restart wpa_supplicant as the nl80211 sockets are closed when cfg80211.ko is unloaded.
> Regards,
> Ilan.

When we remove the WiFi module, the interfaces disappear, when we insert 
it again, the interfaces will appear again. wpa_supplicant will not 
apply the configuration again as it is only applied on the interfaces 
when wpa_supplicant starts. For our use-case it is not desirable to have 
to restart wpa_supplicant when the module is re-inserted so that the 
configuration file is applied on the interfaces provided by the WiFi module.
For wpa_supplicant to be able to make a P2P connection using the module 
we have, we must configure the settings mentioned in the previous mail.

I hope this was the clarification you were looking for, otherwise I'll 
try again.

We have the cfg80211 driver as part of the kernel instead of a module, 
it is never removed.

Best regards // John Ernberg

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