Return-path: Received: from emh04.mail.saunalahti.fi ([62.142.5.110]:35998 "EHLO emh04.mail.saunalahti.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754832AbaCELLu (ORCPT ); Wed, 5 Mar 2014 06:11:50 -0500 From: Luca Coelho To: linux-wireless@vger.kernel.org Cc: johannes@sipsolutions.net, michal.kazior@tieto.com, sw@simonwunderlich.de, andrei.otcheretianski@intel.com Subject: [PATCH v5 1/3] mac80211: split ieee80211_vif_change_channel in two Date: Wed, 5 Mar 2014 13:11:42 +0200 Message-Id: <1394017904-4012-2-git-send-email-luca@coelho.fi> (sfid-20140305_121156_036530_0C5C4D4D) In-Reply-To: <1394017904-4012-1-git-send-email-luca@coelho.fi> References: <1394017904-4012-1-git-send-email-luca@coelho.fi> Sender: linux-wireless-owner@vger.kernel.org List-ID: From: Luciano Coelho ieee80211_vif_change_channel() locks chanctx_mtx. When implementing channel reservation for CS, we will need to call the function to change channel when the lock is already held, so split the part that requires the lock out and leave the locking in the original function. Signed-off-by: Luciano Coelho --- net/mac80211/chan.c | 58 ++++++++++++++++++++++++++++++----------------------- 1 file changed, 33 insertions(+), 25 deletions(-) diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c index 42c6592..a27c6ec 100644 --- a/net/mac80211/chan.c +++ b/net/mac80211/chan.c @@ -547,39 +547,20 @@ int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata, return ret; } -int ieee80211_vif_change_channel(struct ieee80211_sub_if_data *sdata, - u32 *changed) +static int __ieee80211_vif_change_channel(struct ieee80211_sub_if_data *sdata, + struct ieee80211_chanctx *ctx, + u32 *changed) { struct ieee80211_local *local = sdata->local; - struct ieee80211_chanctx_conf *conf; - struct ieee80211_chanctx *ctx; const struct cfg80211_chan_def *chandef = &sdata->csa_chandef; - int ret; u32 chanctx_changed = 0; - lockdep_assert_held(&local->mtx); - - /* should never be called if not performing a channel switch. */ - if (WARN_ON(!sdata->vif.csa_active)) - return -EINVAL; - if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef, IEEE80211_CHAN_DISABLED)) return -EINVAL; - mutex_lock(&local->chanctx_mtx); - conf = rcu_dereference_protected(sdata->vif.chanctx_conf, - lockdep_is_held(&local->chanctx_mtx)); - if (!conf) { - ret = -EINVAL; - goto out; - } - - ctx = container_of(conf, struct ieee80211_chanctx, conf); - if (ctx->refcount != 1) { - ret = -EINVAL; - goto out; - } + if (ctx->refcount != 1) + return -EINVAL; if (sdata->vif.bss_conf.chandef.width != chandef->width) { chanctx_changed = IEEE80211_CHANCTX_CHANGE_WIDTH; @@ -597,7 +578,34 @@ int ieee80211_vif_change_channel(struct ieee80211_sub_if_data *sdata, ieee80211_recalc_radar_chanctx(local, ctx); ieee80211_recalc_chanctx_min_def(local, ctx); - ret = 0; + return 0; +} + +int ieee80211_vif_change_channel(struct ieee80211_sub_if_data *sdata, + u32 *changed) +{ + struct ieee80211_local *local = sdata->local; + struct ieee80211_chanctx_conf *conf; + struct ieee80211_chanctx *ctx; + int ret; + + lockdep_assert_held(&local->mtx); + + /* should never be called if not performing a channel switch. */ + if (WARN_ON(!sdata->vif.csa_active)) + return -EINVAL; + + mutex_lock(&local->chanctx_mtx); + conf = rcu_dereference_protected(sdata->vif.chanctx_conf, + lockdep_is_held(&local->chanctx_mtx)); + if (!conf) { + ret = -EINVAL; + goto out; + } + + ctx = container_of(conf, struct ieee80211_chanctx, conf); + + ret = __ieee80211_vif_change_channel(sdata, ctx, changed); out: mutex_unlock(&local->chanctx_mtx); return ret; -- 1.8.5.3