From 50a9432daeece6fc1309bef1dc0a7b8fde8204cb Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 16 Nov 2010 11:50:28 -0800 Subject: mac80211: fix powersaving clients races The code to handle powersaving stations has a race: when the powersave flag is lifted from a station, we could transmit a packet that is being processed for TX at the same time right away, even if there are other frames queued for it. This would cause frame reordering. To fix this, lift the flag only under the appropriate lock that blocks TX. Additionally, the code to allow drivers to block a station while frames for it are on the HW queue is never re-enabled the station, so traffic would get stuck indefinitely. Fix this by clearing the flag for this appropriately. Finally, as an optimisation, don't do anything if the driver unblocks an already unblocked station. Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- net/mac80211/sta_info.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) (limited to 'net/mac80211/sta_info.c') diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c index 6d8f897d8763..eff58571fd7e 100644 --- a/net/mac80211/sta_info.c +++ b/net/mac80211/sta_info.c @@ -199,8 +199,11 @@ static void sta_unblock(struct work_struct *wk) if (!test_sta_flags(sta, WLAN_STA_PS_STA)) ieee80211_sta_ps_deliver_wakeup(sta); - else if (test_and_clear_sta_flags(sta, WLAN_STA_PSPOLL)) + else if (test_and_clear_sta_flags(sta, WLAN_STA_PSPOLL)) { + clear_sta_flags(sta, WLAN_STA_PS_DRIVER); ieee80211_sta_ps_deliver_poll_response(sta); + } else + clear_sta_flags(sta, WLAN_STA_PS_DRIVER); } static int sta_prepare_rate_control(struct ieee80211_local *local, @@ -880,6 +883,13 @@ struct ieee80211_sta *ieee80211_find_sta(struct ieee80211_vif *vif, } EXPORT_SYMBOL(ieee80211_find_sta); +static void clear_sta_ps_flags(void *_sta) +{ + struct sta_info *sta = _sta; + + clear_sta_flags(sta, WLAN_STA_PS_DRIVER | WLAN_STA_PS_STA); +} + /* powersave support code */ void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta) { @@ -894,7 +904,8 @@ void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta) /* Send all buffered frames to the station */ sent = ieee80211_add_pending_skbs(local, &sta->tx_filtered); - buffered = ieee80211_add_pending_skbs(local, &sta->ps_tx_buf); + buffered = ieee80211_add_pending_skbs_fn(local, &sta->ps_tx_buf, + clear_sta_ps_flags, sta); sent += buffered; local->total_ps_buffered -= buffered; @@ -973,7 +984,7 @@ void ieee80211_sta_block_awake(struct ieee80211_hw *hw, if (block) set_sta_flags(sta, WLAN_STA_PS_DRIVER); - else + else if (test_sta_flags(sta, WLAN_STA_PS_DRIVER)) ieee80211_queue_work(hw, &sta->drv_unblock_wk); } EXPORT_SYMBOL(ieee80211_sta_block_awake); -- cgit v1.2.3