stmmac: fix DMA channel hang in half-duplex mode

[ Upstream commit b6cfffa7ad923c73f317ea50fd4ebcb3b4b6669c ]

HW does not support Half-duplex mode in multi-queue
scenario. Fix it by not advertising the Half-Duplex
mode if multi-queue enabled.

Signed-off-by: Bhadram Varka <vbhadram@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 9866d2e34cdd8165fce6ad75c859566496c272d5..27f2e650e27b9d1dd0c60b2197d8b855a67a203b 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -914,6 +914,7 @@ static void stmmac_check_pcs_mode(struct stmmac_priv *priv)
 static int stmmac_init_phy(struct net_device *dev)
 {
        struct stmmac_priv *priv = netdev_priv(dev);
+       u32 tx_cnt = priv->plat->tx_queues_to_use;
        struct phy_device *phydev;
        char phy_id_fmt[MII_BUS_ID_SIZE + 3];
        char bus_id[MII_BUS_ID_SIZE];
@@ -954,6 +955,15 @@ static int stmmac_init_phy(struct net_device *dev)
                phydev->advertising &= ~(SUPPORTED_1000baseT_Half |
                                         SUPPORTED_1000baseT_Full);
 
+       /*
+        * Half-duplex mode not supported with multiqueue
+        * half-duplex can only works with single queue
+        */
+       if (tx_cnt > 1)
+               phydev->supported &= ~(SUPPORTED_1000baseT_Half |
+                                      SUPPORTED_100baseT_Half |
+                                      SUPPORTED_10baseT_Half);
+
        /*
         * Broken HW is sometimes missing the pull-up resistor on the
         * MDIO line, which results in reads to non-existent devices returning