wl12xx: reset link Tx queues when freeing it

Before, the link was first freed (invalidating it in the map), and later
on vif removal, all valid wlvif-related links were reset. Since these
links were already invalid, we failed to reset them.
The bug was made worse by op_stop, which set the tx_queue_count to 0
arbitrarily. This resulted in a negative tx_queue_count in some scenarios.

Fix this by resetting the Tx-queues of a link when freeing it. Add a
WARN_ON and reset all link Tx-queues in op_stop, to avoid a negative
tx_queue_count.

[changed WARN_ON to WARN_ON_ONCE -- Luca]

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>
diff --git a/drivers/net/wireless/wl12xx/cmd.c b/drivers/net/wireless/wl12xx/cmd.c
index ef994da..ae1f3d7 100644
--- a/drivers/net/wireless/wl12xx/cmd.c
+++ b/drivers/net/wireless/wl12xx/cmd.c
@@ -485,6 +485,13 @@
 	__clear_bit(*hlid, wl->links_map);
 	__clear_bit(*hlid, wlvif->links_map);
 	spin_unlock_irqrestore(&wl->wl_lock, flags);
+
+	/*
+	 * At this point op_tx() will not add more packets to the queues. We
+	 * can purge them.
+	 */
+	wl1271_tx_reset_link_queues(wl, *hlid);
+
 	*hlid = WL12XX_INVALID_LINK_ID;
 }