tg3: Allow ethtool to enable/disable loopback.

This patch adds tg3_set_features() to handle loopback mode. Currently the
capability is added for the devices which support internal MAC loopback mode.
So when enabled, it enables internal-MAC loopback.

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 67 insertions, 2 deletions

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index ec1953043102..d5a1f9e3794c 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -3373,8 +3373,8 @@ relink:
                 tg3_phy_copper_begin(tp);
 
                 tg3_readphy(tp, MII_BMSR, &bmsr);
-                if (!tg3_readphy(tp, MII_BMSR, &bmsr) &&
-                    (bmsr & BMSR_LSTATUS))
+                if ((!tg3_readphy(tp, MII_BMSR, &bmsr) && (bmsr & BMSR_LSTATUS)) ||
+                    (tp->mac_mode & MAC_MODE_PORT_INT_LPBACK))
                         current_link_up = 1;
         }
 
@@ -6309,6 +6309,42 @@ dma_error:
         return NETDEV_TX_OK;
 }
 
+static void tg3_set_loopback(struct net_device *dev, u32 features)
+{
+        struct tg3 *tp = netdev_priv(dev);
+
+        if (features & NETIF_F_LOOPBACK) {
+                if (tp->mac_mode & MAC_MODE_PORT_INT_LPBACK)
+                        return;
+
+                /*
+                 * Clear MAC_MODE_HALF_DUPLEX or you won't get packets back in
+                 * loopback mode if Half-Duplex mode was negotiated earlier.
+                 */
+                tp->mac_mode &= ~MAC_MODE_HALF_DUPLEX;
+
+                /* Enable internal MAC loopback mode */
+                tp->mac_mode |= MAC_MODE_PORT_INT_LPBACK;
+                spin_lock_bh(&tp->lock);
+                tw32(MAC_MODE, tp->mac_mode);
+                netif_carrier_on(tp->dev);
+                spin_unlock_bh(&tp->lock);
+                netdev_info(dev, "Internal MAC loopback mode enabled.\n");
+        } else {
+                if (!(tp->mac_mode & MAC_MODE_PORT_INT_LPBACK))
+                        return;
+
+                /* Disable internal MAC loopback mode */
+                tp->mac_mode &= ~MAC_MODE_PORT_INT_LPBACK;
+                spin_lock_bh(&tp->lock);
+                tw32(MAC_MODE, tp->mac_mode);
+                /* Force link status check */
+                tg3_setup_phy(tp, 1);
+                spin_unlock_bh(&tp->lock);
+                netdev_info(dev, "Internal MAC loopback mode disabled.\n");
+        }
+}
+
 static u32 tg3_fix_features(struct net_device *dev, u32 features)
 {
         struct tg3 *tp = netdev_priv(dev);
@@ -6319,6 +6355,16 @@ static u32 tg3_fix_features(struct net_device *dev, u32 features)
         return features;
 }
 
+static int tg3_set_features(struct net_device *dev, u32 features)
+{
+        u32 changed = dev->features ^ features;
+
+        if ((changed & NETIF_F_LOOPBACK) && netif_running(dev))
+                tg3_set_loopback(dev, features);
+
+        return 0;
+}
+
 static inline void tg3_set_mtu(struct net_device *dev, struct tg3 *tp,
                                int new_mtu)
 {
@@ -9485,6 +9531,13 @@ static int tg3_open(struct net_device *dev)
 
         netif_tx_start_all_queues(dev);
 
+        /*
+         * Reset loopback feature if it was turned on while the device was down
+         * make sure that it's installed properly now.
+         */
+        if (dev->features & NETIF_F_LOOPBACK)
+                tg3_set_loopback(dev, dev->features);
+
         return 0;
 
 err_out3:
@@ -15033,6 +15086,7 @@ static const struct net_device_ops tg3_netdev_ops = {
         .ndo_tx_timeout         = tg3_tx_timeout,
         .ndo_change_mtu         = tg3_change_mtu,
         .ndo_fix_features       = tg3_fix_features,
+        .ndo_set_features       = tg3_set_features,
 #ifdef CONFIG_NET_POLL_CONTROLLER
         .ndo_poll_controller    = tg3_poll_controller,
 #endif
@@ -15049,6 +15103,7 @@ static const struct net_device_ops tg3_netdev_ops_dma_bug = {
         .ndo_do_ioctl           = tg3_ioctl,
         .ndo_tx_timeout         = tg3_tx_timeout,
         .ndo_change_mtu         = tg3_change_mtu,
+        .ndo_set_features       = tg3_set_features,
 #ifdef CONFIG_NET_POLL_CONTROLLER
         .ndo_poll_controller    = tg3_poll_controller,
 #endif
@@ -15246,6 +15301,16 @@ static int __devinit tg3_init_one(struct pci_dev *pdev,
         dev->features |= hw_features;
         dev->vlan_features |= hw_features;
 
+        /*
+         * Add loopback capability only for a subset of devices that support
+         * MAC-LOOPBACK. Eventually this need to be enhanced to allow INT-PHY
+         * loopback for the remaining devices.
+         */
+        if (GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5780 &&
+            !tg3_flag(tp, CPMU_PRESENT))
+                /* Add the loopback capability */
+                dev->hw_features |= NETIF_F_LOOPBACK;
+
         if (tp->pci_chip_rev_id == CHIPREV_ID_5705_A1 &&
             !tg3_flag(tp, TSO_CAPABLE) &&
             !(tr32(TG3PCI_PCISTATE) & PCISTATE_BUS_SPEED_HIGH)) {