[PATCH 5/9] net: mediatek: fix stop and wakeup of queue

[John Crispin]

The driver supports 2 MACs. Both run on the same DMA ring. If we go
above/below the TX rings threshold value, we always need to wake/stop
the queue of both devices. Not doing to can cause TX stalls and packet
drops on one of the devices.

Signed-off-by: John Crispin <blo...@openwrt.org>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c |   37 +++++++++++++++++++--------
 1 file changed, 27 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c 
b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index a4982e4..4ebc42e 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -684,6 +684,28 @@ static inline int mtk_cal_txd_req(struct sk_buff *skb)
        return nfrags;
 }
 
+static void mtk_wake_queue(struct mtk_eth *eth)
+{
+       int i;
+
+       for (i = 0; i < MTK_MAC_COUNT; i++) {
+               if (!eth->netdev[i])
+                       continue;
+               netif_wake_queue(eth->netdev[i]);
+       }
+}
+
+static void mtk_stop_queue(struct mtk_eth *eth)
+{
+       int i;
+
+       for (i = 0; i < MTK_MAC_COUNT; i++) {
+               if (!eth->netdev[i])
+                       continue;
+               netif_stop_queue(eth->netdev[i]);
+       }
+}
+
 static int mtk_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
        struct mtk_mac *mac = netdev_priv(dev);
@@ -695,7 +717,7 @@ static int mtk_start_xmit(struct sk_buff *skb, struct 
net_device *dev)
 
        tx_num = mtk_cal_txd_req(skb);
        if (unlikely(atomic_read(&ring->free_count) <= tx_num)) {
-               netif_stop_queue(dev);
+               mtk_stop_queue(eth);
                netif_err(eth, tx_queued, dev,
                          "Tx Ring full when queue awake!\n");
                return NETDEV_TX_BUSY;
@@ -720,10 +742,10 @@ static int mtk_start_xmit(struct sk_buff *skb, struct 
net_device *dev)
                goto drop;
 
        if (unlikely(atomic_read(&ring->free_count) <= ring->thresh)) {
-               netif_stop_queue(dev);
+               mtk_stop_queue(eth);
                if (unlikely(atomic_read(&ring->free_count) >
                             ring->thresh))
-                       netif_wake_queue(dev);
+                       mtk_wake_queue(eth);
        }
 
        return NETDEV_TX_OK;
@@ -897,13 +919,8 @@ static int mtk_poll_tx(struct mtk_eth *eth, int budget, 
bool *tx_again)
        if (!total)
                return 0;
 
-       for (i = 0; i < MTK_MAC_COUNT; i++) {
-               if (!eth->netdev[i] ||
-                   unlikely(!netif_queue_stopped(eth->netdev[i])))
-                       continue;
-               if (atomic_read(&ring->free_count) > ring->thresh)
-                       netif_wake_queue(eth->netdev[i]);
-       }
+       if (atomic_read(&ring->free_count) > ring->thresh)
+               mtk_wake_queue(eth);
 
        return total;
 }
-- 
1.7.10.4