wl12xx: don't indicate up PS-filtered dummy packets

Dummy packets are currently only sent on the system_hlid link. The
system_hlid link should never be filtered for PS (as it is not
a STA link). Even so, for correctness, don't indicate dummy packets up.
The skb does not belong to mac80211 and as such does not contain a
correct skb->cb.

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>
diff --git a/drivers/net/wireless/wl12xx/ps.c b/drivers/net/wireless/wl12xx/ps.c
index 4b720b1..c15ebf2 100644
--- a/drivers/net/wireless/wl12xx/ps.c
+++ b/drivers/net/wireless/wl12xx/ps.c
@@ -199,15 +199,19 @@
 	unsigned long flags;
 	int filtered[NUM_TX_QUEUES];
 
-	/* filter all frames currently the low level queus for this hlid */
+	/* filter all frames currently in the low level queues for this hlid */
 	for (i = 0; i < NUM_TX_QUEUES; i++) {
 		filtered[i] = 0;
 		while ((skb = skb_dequeue(&wl->links[hlid].tx_queue[i]))) {
+			filtered[i]++;
+
+			if (WARN_ON(wl12xx_is_dummy_packet(wl, skb)))
+				continue;
+
 			info = IEEE80211_SKB_CB(skb);
 			info->flags |= IEEE80211_TX_STAT_TX_FILTERED;
 			info->status.rates[0].idx = -1;
 			ieee80211_tx_status_ni(wl->hw, skb);
-			filtered[i]++;
 		}
 	}
 
diff --git a/drivers/net/wireless/wl12xx/tx.c b/drivers/net/wireless/wl12xx/tx.c
index b8dbc6d..b6b2d3a 100644
--- a/drivers/net/wireless/wl12xx/tx.c
+++ b/drivers/net/wireless/wl12xx/tx.c
@@ -143,7 +143,7 @@
 		wl1271_ps_link_start(wl, hlid, true);
 }
 
-static bool wl12xx_is_dummy_packet(struct wl1271 *wl, struct sk_buff *skb)
+bool wl12xx_is_dummy_packet(struct wl1271 *wl, struct sk_buff *skb)
 {
 	return wl->dummy_packet == skb;
 }
diff --git a/drivers/net/wireless/wl12xx/tx.h b/drivers/net/wireless/wl12xx/tx.h
index 6519be4b..5c0fbbe 100644
--- a/drivers/net/wireless/wl12xx/tx.h
+++ b/drivers/net/wireless/wl12xx/tx.h
@@ -214,5 +214,6 @@
 u8 wl12xx_tx_get_hlid_ap(struct wl1271 *wl, struct sk_buff *skb);
 void wl1271_tx_reset_link_queues(struct wl1271 *wl, u8 hlid);
 void wl1271_handle_tx_low_watermark(struct wl1271 *wl);
+bool wl12xx_is_dummy_packet(struct wl1271 *wl, struct sk_buff *skb);
 
 #endif