Return-path: Received: from mail-wi0-f170.google.com ([209.85.212.170]:60339 "EHLO mail-wi0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751440AbaEZJnM convert rfc822-to-8bit (ORCPT ); Mon, 26 May 2014 05:43:12 -0400 Received: by mail-wi0-f170.google.com with SMTP id bs8so4024248wib.5 for ; Mon, 26 May 2014 02:43:09 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <87y4xoswsa.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> <87y4xoswsa.fsf@kamboji.qca.qualcomm.com> Date: Mon, 26 May 2014 11:43:07 +0200 Message-ID: (sfid-20140526_114315_323280_B7CBA6B7) 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 26 May 2014 11:40, 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 >> --- >> drivers/net/wireless/ath/ath10k/mac.c | 30 ++++++++++++++++++++++++------ >> 1 file changed, 24 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c >> index b5d75b8..577a3a5 100644 >> --- 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)); > > Based on the discussion I modified the function to this now. Are you ok > with that? > > /* Must not be called with conf_mutex held as workers can use that also. */ > static void ath10k_drain_tx(struct ath10k *ar) > { > /* make sure rcu-protected mac80211 tx path itself is drained */ > synchronize_net(); > > ath10k_offchan_tx_purge(ar); > ath10k_mgmt_over_wmi_tx_purge(ar); > > cancel_work_sync(&ar->offchan_tx_work); > cancel_work_sync(&ar->wmi_mgmt_tx_work); > } > > Full patch: > > https://github.com/kvalo/ath/commit/e3c513cd03802e75802a6ce5efbadaa0dbf04b27 Looks good, thanks! Michał