cxgb3 - Fix potential MAC hang

Under rare conditions, the MAC might hang while generating a pause frame.
This patch fine tunes the MAC settings to avoid the issue, allows for
periodic MAC state check, and triggers a recovery if hung.

Also fix one MAC statistics counter for the rev board T3B2.

Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 45 insertions, 1 deletions

diff --git a/drivers/net/cxgb3/cxgb3_main.c b/drivers/net/cxgb3/cxgb3_main.c
index b9bcda821f7c..d55383610559 100644
--- a/drivers/net/cxgb3/cxgb3_main.c
+++ b/drivers/net/cxgb3/cxgb3_main.c
@@ -1056,7 +1056,11 @@ static char stats_strings[][ETH_GSTRING_LEN] = {
         "VLANinsertions     ",
         "TxCsumOffload      ",
         "RxCsumGood         ",
-        "RxDrops            "
+        "RxDrops            ",
+
+        "CheckTXEnToggled   ",
+        "CheckResets        ",
+
 };
 
 static int get_stats_count(struct net_device *dev)
@@ -1170,6 +1174,9 @@ static void get_stats(struct net_device *dev, struct ethtool_stats *stats,
         *data++ = collect_sge_port_stats(adapter, pi, SGE_PSTAT_TX_CSUM);
         *data++ = collect_sge_port_stats(adapter, pi, SGE_PSTAT_RX_CSUM_GOOD);
         *data++ = s->rx_cong_drops;
+
+        *data++ = s->num_toggled;
+        *data++ = s->num_resets;
 }
 
 static inline void reg_block_dump(struct adapter *ap, void *buf,
@@ -2095,6 +2102,40 @@ static void check_link_status(struct adapter *adapter)
         }
 }
 
+static void check_t3b2_mac(struct adapter *adapter)
+{
+        int i;
+
+        rtnl_lock();                      /* synchronize with ifdown */
+        for_each_port(adapter, i) {
+                struct net_device *dev = adapter->port[i];
+                struct port_info *p = netdev_priv(dev);
+                int status;
+
+                if (!netif_running(dev))
+                        continue;
+
+                status = 0;
+                if (netif_running(dev))
+                        status = t3b2_mac_watchdog_task(&p->mac);
+                if (status == 1)
+                        p->mac.stats.num_toggled++;
+                else if (status == 2) {
+                        struct cmac *mac = &p->mac;
+
+                        t3_mac_set_mtu(mac, dev->mtu);
+                        t3_mac_set_address(mac, 0, dev->dev_addr);
+                        cxgb_set_rxmode(dev);
+                        t3_link_start(&p->phy, mac, &p->link_config);
+                        t3_mac_enable(mac, MAC_DIRECTION_RX | MAC_DIRECTION_TX);
+                        t3_port_intr_enable(adapter, p->port_id);
+                        p->mac.stats.num_resets++;
+                }
+        }
+        rtnl_unlock();
+}
+
+
 static void t3_adap_check_task(struct work_struct *work)
 {
         struct adapter *adapter = container_of(work, struct adapter,
@@ -2115,6 +2156,9 @@ static void t3_adap_check_task(struct work_struct *work)
                 adapter->check_task_cnt = 0;
         }
 
+        if (p->rev == T3_REV_B2)
+                check_t3b2_mac(adapter);
+
         /* Schedule the next check update if any port is active. */
         spin_lock(&adapter->work_lock);
         if (adapter->open_device_map & PORT_MASK)