Return-path: Received: from mail-wi0-f172.google.com ([209.85.212.172]:49852 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750969AbaEWIiX convert rfc822-to-8bit (ORCPT ); Fri, 23 May 2014 04:38:23 -0400 Received: by mail-wi0-f172.google.com with SMTP id hi2so454265wib.17 for ; Fri, 23 May 2014 01:38:20 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <87oayovr1m.fsf@kamboji.qca.qualcomm.com> 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> Date: Fri, 23 May 2014 10:38:20 +0200 Message-ID: (sfid-20140523_103831_577790_8E0CCF53) Subject: Re: [PATCH v2 3/5] ath10k: drain tx before restarting hw From: Michal Kazior To: Kalle Valo Cc: "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 10:27, Kalle Valo wrote: > Michal Kazior writes: > >> This makes sure no further tx requests are >> submitted to HTT before driver teardown. >> >> This should prevent invalid pointer/NULL >> dereference on htt tx pool in ath10k_htt_tx() in >> some cases of heavy traffic. >> >> Reported-By: Ben Greear >> Signed-off-by: Michal Kazior > > [...] > >> --- a/drivers/net/wireless/ath/ath10k/mac.c >> +++ b/drivers/net/wireless/ath/ath10k/mac.c >> @@ -2289,6 +2289,21 @@ static void ath10k_tx(struct ieee80211_hw *hw, >> /* >> * Initialize various parameters with default vaules. >> */ >> +static void ath10k_drain_tx(struct ath10k *ar) >> +{ >> + /* workers can hold conf_mutex -- avoid deadlock */ >> + WARN_ON(lockdep_is_held(&ar->conf_mutex)); > > If CONFIG_LOCKDEP is disabled this will fail with: > > drivers/net/wireless/ath/ath10k/mac.c:2301:2: error: implicit declaration of function 'lockdep_is_held' [-Werror=implicit-function-declaration] > > I wasn't able to come up with any other way than adding '#ifdef > CONFIG_LOCKDEP' which is quite ugly. What should we do? I guess we could define lockdep_assert_not_held() in debug.h? Michał