mwifiex: minor cleanups w/ sta_list_spinlock in cfg80211.c

The sta_list_spinlock looks to be used to control locking of the
list. Specifically when someone has the lock they may be allowed
to modify or delete elements of the list.

That implies that we shouldn't access the fields of the elements
returned by mwifiex_get_sta_entry() after we've released the
spinlock. Let's make some small changes so this is true.

It's unlikely that this matters since it looks to be just error
handling, but it's nice to be clean.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Ganapathi Bhat <gbhat@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/marvell/mwifiex/cfg80211.c

@@ -3794,9 +3794,8 @@ mwifiex_cfg80211_tdls_chan_switch(struct wiphy *wiphy, struct net_device *dev,
 
 	spin_lock_irqsave(&priv->sta_list_spinlock, flags);
 	sta_ptr = mwifiex_get_sta_entry(priv, addr);
-	spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
-
 	if (!sta_ptr) {
+		spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
 		wiphy_err(wiphy, "%s: Invalid TDLS peer %pM\n",
 			  __func__, addr);
 		return -ENOENT;
@@ -3804,15 +3803,18 @@ mwifiex_cfg80211_tdls_chan_switch(struct wiphy *wiphy, struct net_device *dev,
 
 	if (!(sta_ptr->tdls_cap.extcap.ext_capab[3] &
 	      WLAN_EXT_CAPA4_TDLS_CHAN_SWITCH)) {
+		spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
 		wiphy_err(wiphy, "%pM do not support tdls cs\n", addr);
 		return -ENOENT;
 	}
 
 	if (sta_ptr->tdls_status == TDLS_CHAN_SWITCHING ||
 	    sta_ptr->tdls_status == TDLS_IN_OFF_CHAN) {
+		spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
 		wiphy_err(wiphy, "channel switch is running, abort request\n");
 		return -EALREADY;
 	}
+	spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
 
 	chan = chandef->chan->hw_value;
 	second_chan_offset = mwifiex_get_sec_chan_offset(chan);
@@ -3833,18 +3835,20 @@ mwifiex_cfg80211_tdls_cancel_chan_switch(struct wiphy *wiphy,
 
 	spin_lock_irqsave(&priv->sta_list_spinlock, flags);
 	sta_ptr = mwifiex_get_sta_entry(priv, addr);
-	spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
-
 	if (!sta_ptr) {
+		spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
 		wiphy_err(wiphy, "%s: Invalid TDLS peer %pM\n",
 			  __func__, addr);
 	} else if (!(sta_ptr->tdls_status == TDLS_CHAN_SWITCHING ||
 		     sta_ptr->tdls_status == TDLS_IN_BASE_CHAN ||
 		     sta_ptr->tdls_status == TDLS_IN_OFF_CHAN)) {
+		spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
 		wiphy_err(wiphy, "tdls chan switch not initialize by %pM\n",
 			  addr);
-	} else
+	} else {
+		spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
 		mwifiex_stop_tdls_cs(priv, addr);
+	}
 }
 
 static int

drivers/net/wireless/marvell/mwifiex/sta_event.c

@@ -359,13 +359,12 @@ static void mwifiex_process_uap_tx_pause(struct mwifiex_private *priv,
 	} else {
 		spin_lock_irqsave(&priv->sta_list_spinlock, flags);
 		sta_ptr = mwifiex_get_sta_entry(priv, tp->peermac);
-		spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
-
 		if (sta_ptr && sta_ptr->tx_pause != tp->tx_pause) {
 			sta_ptr->tx_pause = tp->tx_pause;
 			mwifiex_update_ralist_tx_pause(priv, tp->peermac,
 						       tp->tx_pause);
 		}
+		spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
 	}
 }
 
@@ -396,14 +395,13 @@ static void mwifiex_process_sta_tx_pause(struct mwifiex_private *priv,
 		if (mwifiex_is_tdls_link_setup(status)) {
 			spin_lock_irqsave(&priv->sta_list_spinlock, flags);
 			sta_ptr = mwifiex_get_sta_entry(priv, tp->peermac);
-			spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
-
 			if (sta_ptr && sta_ptr->tx_pause != tp->tx_pause) {
 				sta_ptr->tx_pause = tp->tx_pause;
 				mwifiex_update_ralist_tx_pause(priv,
 							       tp->peermac,
 							       tp->tx_pause);
 			}
+			spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
 		}
 	}
 }