From patchwork Mon Mar 30 07:49:22 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Berg X-Patchwork-Id: 6118661 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: X-Original-To: patchwork-linux-wireless@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 7FFBE9F349 for ; Mon, 30 Mar 2015 07:49:31 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 87E65202A1 for ; Mon, 30 Mar 2015 07:49:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C255201DD for ; Mon, 30 Mar 2015 07:49:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752724AbbC3Ht1 (ORCPT ); Mon, 30 Mar 2015 03:49:27 -0400 Received: from s3.sipsolutions.net ([5.9.151.49]:45434 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752577AbbC3Ht0 (ORCPT ); Mon, 30 Mar 2015 03:49:26 -0400 Received: by sipsolutions.net with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_CBC_SHA256:128) (Exim 4.84) (envelope-from ) id 1YcURo-0005Qr-2D; Mon, 30 Mar 2015 09:49:24 +0200 From: Johannes Berg To: linux-wireless@vger.kernel.org Cc: Johannes Berg Subject: [PATCH] mac80211: agg-tx: avoid sending DelBA with sta->lock held Date: Mon, 30 Mar 2015 09:49:22 +0200 Message-Id: <1427701762-27090-1-git-send-email-johannes@sipsolutions.net> X-Mailer: git-send-email 2.1.4 Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Johannes Berg The rate control locking caused a potential deadlock here due to the locks being acquired in different orders, so that change cannot yet be applied. However, there's no fundamental reason for this code to hold the sta->lock while transmitting frames. Clearly it's better not to hold the lock for longer periods of time, which can happen here since we call all the way down to the driver. Change the code a bit to not hold it while doing that. Signed-off-by: Johannes Berg --- net/mac80211/agg-tx.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c index a360c15cc978..668524aeb0b2 100644 --- a/net/mac80211/agg-tx.c +++ b/net/mac80211/agg-tx.c @@ -793,6 +793,7 @@ void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid) struct ieee80211_local *local = sdata->local; struct sta_info *sta; struct tid_ampdu_tx *tid_tx; + bool send_delba = false; trace_api_stop_tx_ba_cb(sdata, ra, tid); @@ -824,13 +825,17 @@ void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid) } if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop) - ieee80211_send_delba(sta->sdata, ra, tid, - WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE); + send_delba = true; ieee80211_remove_tid_tx(sta, tid); unlock_sta: spin_unlock_bh(&sta->lock); + + if (send_delba) + ieee80211_send_delba(sdata, ra, tid, + WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE); + mutex_unlock(&sta->ampdu_mlme.mtx); unlock: mutex_unlock(&local->sta_mtx);