openwrt/target/linux/mediatek/patches-4.4/0091-net-next-mediatek-only-wake-the-queue-if-it-is-stopp.patch

From 1473b4cce85760c0202a08e6a48ec51867dc1bf7 Mon Sep 17 00:00:00 2001
From: John Crispin <john@phrozen.org>
Date: Tue, 3 May 2016 04:01:38 +0200
Subject: [PATCH 091/102] net-next: mediatek: only wake the queue if it is
 stopped

The current code unconditionally wakes up the queue at the end of each
tx_poll action. Change the code to only wake up the queues if any of
them have actually been stopped before.

Signed-off-by: John Crispin <john@phrozen.org>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c |   17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -716,6 +716,20 @@ static inline int mtk_cal_txd_req(struct
 	return nfrags;
 }
 
+static int mtk_queue_stopped(struct mtk_eth *eth)
+{
+	int i;
+
+	for (i = 0; i < MTK_MAC_COUNT; i++) {
+		if (!eth->netdev[i])
+			continue;
+		if (netif_queue_stopped(eth->netdev[i]))
+			return 1;
+	}
+
+	return 0;
+}
+
 static void mtk_wake_queue(struct mtk_eth *eth)
 {
 	int i;
@@ -960,7 +974,8 @@ static int mtk_poll_tx(struct mtk_eth *e
 	if (!total)
 		return 0;
 
-	if (atomic_read(&ring->free_count) > ring->thresh)
+	if (mtk_queue_stopped(eth) &&
+	    (atomic_read(&ring->free_count) > ring->thresh))
 		mtk_wake_queue(eth);
 
 	return total;