Message-ID: <1427872324.2432.3.camel@sipsolutions.net> (sfid-20150401_091212_460071_A7C8AD99)
Subject: Re: [PATCH 7/7] mac80211: Count correctly interface types
From: Johannes Berg <johannes@sipsolutions.net>
To: Janusz Dziedzic <janusz.dziedzic@tieto.com>,
	Ilan Peer <ilan.peer@intel.com>
Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com>,
	linux-wireless@vger.kernel.org,
	Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Date: Wed, 01 Apr 2015 09:12:04 +0200
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References: <1426143210-25635-1-git-send-email-emmanuel.grumbach@intel.com>
	 <1426143210-25635-7-git-send-email-emmanuel.grumbach@intel.com>
	 <CALhHN=qkEmUPEL2XBuuudmq6Rg-6s7jm0TOdRuQCetgSiKyrpg@mail.gmail.com>
	 (sfid-20150401_080606_876573_33E52A4C)
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On Wed, 2015-04-01 at 08:06 +0200, Janusz Dziedzic wrote:

> Hello,
> 
> Seems this one break IBSS case when started from wpa_supplicant at
> least for Intel7260 and ath10k where dedicated p2p_device is used.
> 
> This is wpa_supplicant log:
> 1427867673.149187: nl80211: Set mode ifindex 8 iftype 1 (ADHOC)
> 1427867673.149225: nl80211: Mode change succeeded while interface is down
> 1427867673.149234: Could not set interface wlan3 flags (UP): Device or
> resource busy

That's actually the correct behaviour, given the interface limitations,
at least for iwlmvm devices:

iw list
[...]
	Supported interface modes:
		 * IBSS
		 * managed
		 * AP
		 * AP/VLAN
		 * monitor
		 * P2P-client
		 * P2P-GO
		 * P2P-device
[...]
	software interface modes (can always be added):
		 * AP/VLAN
		 * monitor
	valid interface combinations:
		 * #{ managed } <= 1, #{ AP, P2P-client, P2P-GO } <= 1, #{ P2P-device } <= 1,
		   total <= 3, #channels <= 2

So there's no combination with P2P-device and IBSS together.

In our device I'm pretty sure the two couldn't be supported together.
Perhaps the supplicant has issues though with how it creates the
P2P-Device? Should probably not be there if you have IBSS, it's pretty
useless anyway then. Or at least not be there if the driver doesn't
advertise support for that combination.

johannes