Return-path: Received: from mail-wi0-f181.google.com ([209.85.212.181]:65247 "EHLO mail-wi0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751128AbaEZFs6 convert rfc822-to-8bit (ORCPT ); Mon, 26 May 2014 01:48:58 -0400 Received: by mail-wi0-f181.google.com with SMTP id n15so3710984wiw.2 for ; Sun, 25 May 2014 22:48:57 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1400850209.4358.31.camel@jlt4.sipsolutions.net> References: <1399637749-13489-1-git-send-email-michal.kazior@tieto.com> <1400143324-14911-1-git-send-email-michal.kazior@tieto.com> <1400143324-14911-4-git-send-email-michal.kazior@tieto.com> <87oayovr1m.fsf@kamboji.qca.qualcomm.com> <87bnuovq6x.fsf@kamboji.qca.qualcomm.com> <1400850209.4358.31.camel@jlt4.sipsolutions.net> Date: Mon, 26 May 2014 07:48:56 +0200 Message-ID: (sfid-20140526_074901_869359_5BB0370C) Subject: Re: [PATCH v2 3/5] ath10k: drain tx before restarting hw From: Michal Kazior To: Johannes Berg Cc: Kalle Valo , "ath10k@lists.infradead.org" , linux-wireless Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 23 May 2014 15:03, Johannes Berg wrote: > On Fri, 2014-05-23 at 11:06 +0200, Michal Kazior wrote: > >> There's nothing wrong with other thread holding it. Actually that's >> the reason for this very check. >> >> The point is to prevent ath10k_drain_tx() being called while caller >> (current thread) holds conf_mutex. If it were to hold conf_mutex then >> cancel_work_sync() can deadlock as both workers it tries to stop try >> to get a hold of the lock too. > > That seems pointless - lockdep would warn you about that *anyway* > because cancel_work_sync() and friends have proper annotations. Try it > sometime :) Does it splat every time or just by chance or after a deadlock? Michał