Return-path: Received: from mail-wm0-f50.google.com ([74.125.82.50]:37716 "EHLO mail-wm0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750989AbcAZGfr convert rfc822-to-8bit (ORCPT ); Tue, 26 Jan 2016 01:35:47 -0500 Received: by mail-wm0-f50.google.com with SMTP id n5so113862538wmn.0 for ; Mon, 25 Jan 2016 22:35:46 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <56A66298.1000607@candelatech.com> References: <1453382588-27105-1-git-send-email-michal.kazior@tieto.com> <56A66298.1000607@candelatech.com> Date: Tue, 26 Jan 2016 07:35:45 +0100 Message-ID: (sfid-20160126_073550_352982_501E73E6) Subject: Re: [PATCH 1/2] mac80211: fix txq queue related crashes From: Michal Kazior To: Ben Greear Cc: linux-wireless , Johannes Berg Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 25 January 2016 at 18:59, Ben Greear wrote: > On 01/21/2016 05:23 AM, Michal Kazior wrote: >> >> The driver can access the queue simultanously >> while mac80211 tears down the interface. Without >> spinlock protection this could lead to corrupting >> sk_buff_head and subsequently to an invalid >> pointer dereference. > > Hard to know for certain, but this *appears* to fix the unexpectedly large > amount of CE/AXI ath10k firmware crashes that we saw in the 4.2 kernel (4.0 > previously > ran much better han 4.2 for us). That's impossible. Without wake_tx_queue() txqs aren't even allocated (sdata->vif.txq is NULL). Michał