Return-path: Received: from s3.sipsolutions.net ([5.9.151.49]:36209 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752378AbbAGNuU (ORCPT ); Wed, 7 Jan 2015 08:50:20 -0500 Message-ID: <1420638611.3407.14.camel@sipsolutions.net> (sfid-20150107_145022_838895_79F0BC76) Subject: Re: [PATCH] cfg80211: fix deadlock during reg chan check From: Johannes Berg To: Arik Nemtsov Cc: "linux-wireless@vger.kernel.org" , "Luis R. Rodriguez" Date: Wed, 07 Jan 2015 14:50:11 +0100 In-Reply-To: (sfid-20150107_144913_204913_20AF85C1) References: <1419847199-25493-1-git-send-email-arik@wizery.com> <1420541514.1966.16.camel@sipsolutions.net> <1420637871.3407.10.camel@sipsolutions.net> <1420638389.3407.13.camel@sipsolutions.net> (sfid-20150107_144913_204913_20AF85C1) Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Wed, 2015-01-07 at 15:48 +0200, Arik Nemtsov wrote: > > > >> > > >> >> > Also, the only reason this can happen anyway is when you call "can > >> >> > beacon" for a station interface - which seems nonsensical. Given that > >> >> > >> >> This is not true. This happens with current code for a p2p-go > >> >> interface during channel validity checks in reg.c. > >> > > >> > Not sure I see this? The only thing doing wdev locking is > >> > cfg80211_go_permissive_chan(), no? And that only for station interfaces. > >> > >> cfg80211_go_permissive_chan is called from cfg80211_reg_can_beacon, > >> currently only for GO interfaces, but for STA also in the future > >> (hopefully). > >> The latter is called during channel validity checks for GO. > > > > Ok. > > > > Should I just apply the patch as it is then? > > It fixes a real existing deadlock, so I think so, yea. Is it needed on 3.19? johannes