ixgbe: Fix interrupt configuration for 82599

The interrupt models using EITR have changed in 82599.  The way the register
is laid out, the change is transparent to some of the existing code.
However, some of it isn't.  This patch fixes all the cases where EITR
handling is different than 82598.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 14 insertions, 7 deletions

diff --git a/drivers/net/ixgbe/ixgbe_ethtool.c b/drivers/net/ixgbe/ixgbe_ethtool.c
index ae38bcaa7ca..3a99781794d 100644
--- a/drivers/net/ixgbe/ixgbe_ethtool.c
+++ b/drivers/net/ixgbe/ixgbe_ethtool.c
@@ -977,40 +977,47 @@ static int ixgbe_set_coalesce(struct net_device *netdev,
                               struct ethtool_coalesce *ec)
 {
 	struct ixgbe_adapter *adapter = netdev_priv(netdev);
-	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;
 
 	if (ec->rx_coalesce_usecs > 1) {
+		/* check the limits */
+		if ((1000000/ec->rx_coalesce_usecs > IXGBE_MAX_INT_RATE) ||
+		    (1000000/ec->rx_coalesce_usecs < IXGBE_MIN_INT_RATE))
+			return -EINVAL;
+
 		/* 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 */
+		/* clear the lower bit as its used for dynamic state */
 		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;
+		/*
+		 * any other value means disable eitr, which is best
+		 * served by setting the interrupt rate very high
+		 */
+		adapter->eitr_param = IXGBE_MAX_INT_RATE;
 		adapter->itr_setting = 0;
 	}
 
 	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)
+			/* tx vector gets half the rate */
 			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));
+		ixgbe_write_eitr(adapter, i,
+		                 EITR_INTS_PER_SEC_TO_REG(q_vector->eitr));
 	}
 
 	return 0;