wl12xx: use round-robin policy for tx

Currently, a single vif might starve all the other vifs.
Save the last vif we dequeued a packet from, and continue
with the following one using a round-robin policy.
Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>

drivers/net/wireless/wl12xx/main.c

@@ -2282,6 +2282,8 @@ static void __wl1271_op_remove_interface(struct wl1271 *wl,
 
 	wl12xx_tx_reset_wlvif(wl, wlvif);
 	wl1271_free_ap_keys(wl, wlvif);
+	if (wl->last_wlvif == wlvif)
+		wl->last_wlvif = NULL;
 	list_del(&wlvif->list);
 	memset(wlvif->ap.sta_hlid_map, 0, sizeof(wlvif->ap.sta_hlid_map));
 	wlvif->role_id = WL12XX_INVALID_ROLE_ID;

drivers/net/wireless/wl12xx/tx.c

@@ -590,14 +590,28 @@ static struct sk_buff *wl12xx_vif_skb_dequeue(struct wl1271 *wl,
 static struct sk_buff *wl1271_skb_dequeue(struct wl1271 *wl)
 {
 	unsigned long flags;
-	struct wl12xx_vif *wlvif;
+	struct wl12xx_vif *wlvif = wl->last_wlvif;
 	struct sk_buff *skb = NULL;
 
-	/* TODO: rememeber last vif and consider it */
-	wl12xx_for_each_wlvif(wl, wlvif) {
-		skb = wl12xx_vif_skb_dequeue(wl, wlvif);
-		if (skb)
-			break;
+	if (wlvif) {
+		wl12xx_for_each_wlvif_continue(wl, wlvif) {
+			skb = wl12xx_vif_skb_dequeue(wl, wlvif);
+			if (skb) {
+				wl->last_wlvif = wlvif;
+				break;
+			}
+		}
+	}
+
+	/* do another pass */
+	if (!skb) {
+		wl12xx_for_each_wlvif(wl, wlvif) {
+			skb = wl12xx_vif_skb_dequeue(wl, wlvif);
+			if (skb) {
+				wl->last_wlvif = wlvif;
+				break;
+			}
+		}
 	}
 
 	if (!skb &&

drivers/net/wireless/wl12xx/wl12xx.h

@@ -552,6 +552,9 @@ struct wl1271 {
 
 	/* AP-mode - number of currently connected stations */
 	int active_sta_count;
+
+	/* last wlvif we transmitted from */
+	struct wl12xx_vif *last_wlvif;
 };
 
 struct wl1271_station {
@@ -693,6 +696,9 @@ struct ieee80211_vif *wl12xx_wlvif_to_vif(struct wl12xx_vif *wlvif)
 #define wl12xx_for_each_wlvif(wl, wlvif) \
 		list_for_each_entry(wlvif, &wl->wlvif_list, list)
 
+#define wl12xx_for_each_wlvif_continue(wl, wlvif) \
+		list_for_each_entry_continue(wlvif, &wl->wlvif_list, list)
+
 #define wl12xx_for_each_wlvif_bss_type(wl, wlvif, _bss_type)	\
 		wl12xx_for_each_wlvif(wl, wlvif)		\
 			if (wlvif->bss_type == _bss_type)