From f0d9e712e459332ec527802f7eaca104c47b14c2 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Sat, 18 Oct 2014 17:38:59 +0000 Subject: mac80211: update to 2014-10-08 Signed-off-by: Felix Fietkau SVN-Revision: 42952 --- .../325-ath9k-Do-not-start-BA-when-scanning.patch | 60 ++++++++++++++++++++++ 1 file changed, 60 insertions(+) create mode 100644 package/kernel/mac80211/patches/325-ath9k-Do-not-start-BA-when-scanning.patch (limited to 'package/kernel/mac80211/patches/325-ath9k-Do-not-start-BA-when-scanning.patch') diff --git a/package/kernel/mac80211/patches/325-ath9k-Do-not-start-BA-when-scanning.patch b/package/kernel/mac80211/patches/325-ath9k-Do-not-start-BA-when-scanning.patch new file mode 100644 index 0000000000..69eb58c50f --- /dev/null +++ b/package/kernel/mac80211/patches/325-ath9k-Do-not-start-BA-when-scanning.patch @@ -0,0 +1,60 @@ +From: Sujith Manoharan +Date: Fri, 17 Oct 2014 07:40:30 +0530 +Subject: [PATCH] ath9k: Do not start BA when scanning + +mac80211 currently has a race which can be hit +with this sequence: + +* Start a scan operation. +* TX BA is initiated by ieee80211_start_tx_ba_session(). +* Driver sets up internal state and calls + ieee80211_start_tx_ba_cb_irqsafe(). +* mac80211 adds a packet to sdata->skb_queue with + type IEEE80211_SDATA_QUEUE_AGG_START. +* ieee80211_iface_work() doesn't process the + packet because scan is in progress. +* ADDBA response timer expires and the sta/tid is + torn down. +* Driver receives BA stop notification and calls + ieee80211_stop_tx_ba_cb_irqsafe(). +* This is also added to the queue by mac80211. +* Now, scan finishes. + +At this point, the queued up packets might be processed +if some other operation schedules the sdata work. Since +the tids have been cleaned up already, warnings are hit. + +If this doesn't happen, the packets are left in the queue +until the interface is torn down. + +Since initiating a BA session when scan is in progress +leads to flaky connections, especially in MCC mode, we +can drop the TX BA request. This improves connectivity +with legacy clients in MCC mode. + +Signed-off-by: Sujith Manoharan +--- + +--- a/drivers/net/wireless/ath/ath9k/main.c ++++ b/drivers/net/wireless/ath/ath9k/main.c +@@ -1885,6 +1885,7 @@ static int ath9k_ampdu_action(struct iee + u16 tid, u16 *ssn, u8 buf_size) + { + struct ath_softc *sc = hw->priv; ++ struct ath_common *common = ath9k_hw_common(sc->sc_ah); + bool flush = false; + int ret = 0; + +@@ -1896,6 +1897,12 @@ static int ath9k_ampdu_action(struct iee + case IEEE80211_AMPDU_RX_STOP: + break; + case IEEE80211_AMPDU_TX_START: ++ if (ath9k_is_chanctx_enabled()) { ++ if (test_bit(ATH_OP_SCANNING, &common->op_flags)) { ++ ret = -EBUSY; ++ break; ++ } ++ } + ath9k_ps_wakeup(sc); + ret = ath_tx_aggr_start(sc, sta, tid, ssn); + if (!ret) -- cgit v1.2.3