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Commit 9c6dda4e authored by Sujith's avatar Sujith Committed by John W. Linville
Browse files

ath9k_htc: Fix beaconing in IBSS mode 



The current way of managing beaconing in ad-hoc
mode has a subtle race - the beacon obtained from mac80211
is freed in the SWBA handler rather than the TX
completion routine. But transmission of beacons goes
through the normal SKB queue maintained in hif_usb,
leading to a situation where __skb_dequeue() in the TX
completion handler goes kaput.

Fix this by simply getting a beacon from mac80211 for
every SWBA and free it in its completion routine.

Signed-off-by: default avatarSujith <Sujith.Manoharan@atheros.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 0aaffa9b

drivers/net/wireless/ath/ath9k/htc.h

+2 −3
Original line number Diff line number Diff line
@@ -356,7 +356,6 @@ struct ath9k_htc_priv { 
	u16 seq_no;

	u32 bmiss_cnt;



	struct sk_buff *beacon;

	spinlock_t beacon_lock;



	bool tx_queues_stop;
@@ -408,13 +407,13 @@ static inline void ath_read_cachesize(struct ath_common *common, int *csz) 
void ath9k_htc_beacon_config(struct ath9k_htc_priv *priv,

			     struct ieee80211_vif *vif);

void ath9k_htc_swba(struct ath9k_htc_priv *priv, u8 beacon_pending);

void ath9k_htc_beacon_update(struct ath9k_htc_priv *priv,

			     struct ieee80211_vif *vif);



void ath9k_htc_rxep(void *priv, struct sk_buff *skb,

		    enum htc_endpoint_id ep_id);

void ath9k_htc_txep(void *priv, struct sk_buff *skb, enum htc_endpoint_id ep_id,

		    bool txok);

void ath9k_htc_beaconep(void *drv_priv, struct sk_buff *skb,

			enum htc_endpoint_id ep_id, bool txok);



void ath9k_htc_station_work(struct work_struct *work);

void ath9k_htc_aggr_work(struct work_struct *work);

drivers/net/wireless/ath/ath9k/htc_drv_beacon.c

+10 −29
Original line number Diff line number Diff line
@@ -165,22 +165,10 @@ static void ath9k_htc_beacon_config_adhoc(struct ath9k_htc_priv *priv, 
	WMI_CMD_BUF(WMI_ENABLE_INTR_CMDID, &htc_imask);

}



void ath9k_htc_beacon_update(struct ath9k_htc_priv *priv,

			     struct ieee80211_vif *vif)

void ath9k_htc_beaconep(void *drv_priv, struct sk_buff *skb,

			enum htc_endpoint_id ep_id, bool txok)

{

	struct ath_common *common = ath9k_hw_common(priv->ah);



	spin_lock_bh(&priv->beacon_lock);



	if (priv->beacon)

		dev_kfree_skb_any(priv->beacon);



	priv->beacon = ieee80211_beacon_get(priv->hw, vif);

	if (!priv->beacon)

		ath_print(common, ATH_DBG_BEACON,

			  "Unable to allocate beacon\n");



	spin_unlock_bh(&priv->beacon_lock);

	dev_kfree_skb_any(skb);

}



void ath9k_htc_swba(struct ath9k_htc_priv *priv, u8 beacon_pending)
@@ -189,6 +177,7 @@ void ath9k_htc_swba(struct ath9k_htc_priv *priv, u8 beacon_pending) 
	struct tx_beacon_header beacon_hdr;

	struct ath9k_htc_tx_ctl tx_ctl;

	struct ieee80211_tx_info *info;

	struct sk_buff *beacon;

	u8 *tx_fhdr;



	memset(&beacon_hdr, 0, sizeof(struct tx_beacon_header));
@@ -207,25 +196,17 @@ void ath9k_htc_swba(struct ath9k_htc_priv *priv, u8 beacon_pending) 
		return;

	}



	if (unlikely(priv->beacon == NULL)) {

		spin_unlock_bh(&priv->beacon_lock);

		return;

	}



	/* Free the old SKB first */

	dev_kfree_skb_any(priv->beacon);



	/* Get a new beacon */

	priv->beacon = ieee80211_beacon_get(priv->hw, priv->vif);

	if (!priv->beacon) {

	beacon = ieee80211_beacon_get(priv->hw, priv->vif);

	if (!beacon) {

		spin_unlock_bh(&priv->beacon_lock);

		return;

	}



	info = IEEE80211_SKB_CB(priv->beacon);

	info = IEEE80211_SKB_CB(beacon);

	if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) {

		struct ieee80211_hdr *hdr =

			(struct ieee80211_hdr *) priv->beacon->data;

			(struct ieee80211_hdr *) beacon->data;

		priv->seq_no += 0x10;

		hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);

		hdr->seq_ctrl |= cpu_to_le16(priv->seq_no);
@@ -233,10 +214,10 @@ void ath9k_htc_swba(struct ath9k_htc_priv *priv, u8 beacon_pending) 


	tx_ctl.type = ATH9K_HTC_NORMAL;

	beacon_hdr.vif_index = avp->index;

	tx_fhdr = skb_push(priv->beacon, sizeof(beacon_hdr));

	tx_fhdr = skb_push(beacon, sizeof(beacon_hdr));

	memcpy(tx_fhdr, (u8 *) &beacon_hdr, sizeof(beacon_hdr));



	htc_send(priv->htc, priv->beacon, priv->beacon_ep, &tx_ctl);

	htc_send(priv->htc, beacon, priv->beacon_ep, &tx_ctl);



	spin_unlock_bh(&priv->beacon_lock);

}

drivers/net/wireless/ath/ath9k/htc_drv_init.c

+1 −1
Original line number Diff line number Diff line
@@ -144,7 +144,7 @@ static int ath9k_init_htc_services(struct ath9k_htc_priv *priv) 
		goto err;



	/* Beacon */

	ret = ath9k_htc_connect_svc(priv, WMI_BEACON_SVC, NULL,

	ret = ath9k_htc_connect_svc(priv, WMI_BEACON_SVC, ath9k_htc_beaconep,

				    &priv->beacon_ep);

	if (ret)

		goto err;

drivers/net/wireless/ath/ath9k/htc_drv_main.c

+0 −12
Original line number Diff line number Diff line
@@ -1313,15 +1313,6 @@ static void ath9k_htc_remove_interface(struct ieee80211_hw *hw, 
	priv->nvifs--;



	ath9k_htc_remove_station(priv, vif, NULL);



	if (vif->type == NL80211_IFTYPE_ADHOC) {

		spin_lock_bh(&priv->beacon_lock);

		if (priv->beacon)

			dev_kfree_skb_any(priv->beacon);

		priv->beacon = NULL;

		spin_unlock_bh(&priv->beacon_lock);

	}



	priv->vif = NULL;



	mutex_unlock(&priv->mutex);
@@ -1590,9 +1581,6 @@ static void ath9k_htc_bss_info_changed(struct ieee80211_hw *hw, 
		ath9k_htc_beacon_config(priv, vif);

	}



	if (changed & BSS_CHANGED_BEACON)

		ath9k_htc_beacon_update(priv, vif);



	if ((changed & BSS_CHANGED_BEACON_ENABLED) &&

	    !bss_conf->enable_beacon) {

		priv->op_flags &= ~OP_ENABLE_BEACON;