ixgbe: fix initial interrupt throttle settings

ixgbe was incorrectly setting the throttle rate setting for all tx
queues and the driver has been refreshed to better handle a dynamic
interrupt mode as well as multiple queues.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 47 insertions, 39 deletions

diff --git a/drivers/net/ixgbe/ixgbe_ethtool.c b/drivers/net/ixgbe/ixgbe_ethtool.c
index 2506f9eae58e..f18e3daaf4f5 100644
--- a/drivers/net/ixgbe/ixgbe_ethtool.c
+++ b/drivers/net/ixgbe/ixgbe_ethtool.c
@@ -880,17 +880,23 @@ static int ixgbe_get_coalesce(struct net_device *netdev,
 {
         struct ixgbe_adapter *adapter = netdev_priv(netdev);
 
-        if (adapter->rx_eitr < IXGBE_MIN_ITR_USECS)
-                ec->rx_coalesce_usecs = adapter->rx_eitr;
-        else
-                ec->rx_coalesce_usecs = 1000000 / adapter->rx_eitr;
-
-        if (adapter->tx_eitr < IXGBE_MIN_ITR_USECS)
-                ec->tx_coalesce_usecs = adapter->tx_eitr;
-        else
-                ec->tx_coalesce_usecs = 1000000 / adapter->tx_eitr;
-
         ec->tx_max_coalesced_frames_irq = adapter->tx_ring[0].work_limit;
+
+        /* only valid if in constant ITR mode */
+        switch (adapter->itr_setting) {
+        case 0:
+                /* throttling disabled */
+                ec->rx_coalesce_usecs = 0;
+                break;
+        case 1:
+                /* dynamic ITR mode */
+                ec->rx_coalesce_usecs = 1;
+                break;
+        default:
+                /* fixed interrupt rate mode */
+                ec->rx_coalesce_usecs = 1000000/adapter->eitr_param;
+                break;
+        }
         return 0;
 }
 
@@ -898,38 +904,40 @@ static int ixgbe_set_coalesce(struct net_device *netdev,
                               struct ethtool_coalesce *ec)
 {
         struct ixgbe_adapter *adapter = netdev_priv(netdev);
-
-        if ((ec->rx_coalesce_usecs > IXGBE_MAX_ITR_USECS) ||
-            ((ec->rx_coalesce_usecs != 0) &&
-             (ec->rx_coalesce_usecs != 1) &&
-             (ec->rx_coalesce_usecs != 3) &&
-             (ec->rx_coalesce_usecs < IXGBE_MIN_ITR_USECS)))
-                return -EINVAL;
-        if ((ec->tx_coalesce_usecs > IXGBE_MAX_ITR_USECS) ||
-            ((ec->tx_coalesce_usecs != 0) &&
-             (ec->tx_coalesce_usecs != 1) &&
-             (ec->tx_coalesce_usecs != 3) &&
-             (ec->tx_coalesce_usecs < IXGBE_MIN_ITR_USECS)))
-                return -EINVAL;
-
-        /* convert to rate of irq's per second */
-        if (ec->rx_coalesce_usecs < IXGBE_MIN_ITR_USECS)
-                adapter->rx_eitr = ec->rx_coalesce_usecs;
-        else
-                adapter->rx_eitr = (1000000 / ec->rx_coalesce_usecs);
-
-        if (ec->tx_coalesce_usecs < IXGBE_MIN_ITR_USECS)
-                adapter->tx_eitr = ec->rx_coalesce_usecs;
-        else
-                adapter->tx_eitr = (1000000 / ec->tx_coalesce_usecs);
+        struct ixgbe_hw *hw = &adapter->hw;
+        int i;
 
         if (ec->tx_max_coalesced_frames_irq)
-                adapter->tx_ring[0].work_limit =
-                                        ec->tx_max_coalesced_frames_irq;
+                adapter->tx_ring[0].work_limit = ec->tx_max_coalesced_frames_irq;
+
+        if (ec->rx_coalesce_usecs > 1) {
+                /* store the value in ints/second */
+                adapter->eitr_param = 1000000/ec->rx_coalesce_usecs;
+
+                /* static value of interrupt rate */
+                adapter->itr_setting = adapter->eitr_param;
+                /* clear the lower bit */
+                adapter->itr_setting &= ~1;
+        } else if (ec->rx_coalesce_usecs == 1) {
+                /* 1 means dynamic mode */
+                adapter->eitr_param = 20000;
+                adapter->itr_setting = 1;
+        } else {
+                /* any other value means disable eitr, which is best
+                 * served by setting the interrupt rate very high */
+                adapter->eitr_param = 3000000;
+                adapter->itr_setting = 0;
+        }
 
-        if (netif_running(netdev)) {
-                ixgbe_down(adapter);
-                ixgbe_up(adapter);
+        for (i = 0; i < adapter->num_msix_vectors - NON_Q_VECTORS; i++) {
+                struct ixgbe_q_vector *q_vector = &adapter->q_vector[i];
+                if (q_vector->txr_count && !q_vector->rxr_count)
+                        q_vector->eitr = (adapter->eitr_param >> 1);
+                else
+                        /* rx only or mixed */
+                        q_vector->eitr = adapter->eitr_param;
+                IXGBE_WRITE_REG(hw, IXGBE_EITR(i),
+                                EITR_INTS_PER_SEC_TO_REG(q_vector->eitr));
         }
 
         return 0;