1 files changed, 53 insertions, 37 deletions

diff --git a/drivers/net/ixgbe/ixgbe_ethtool.c b/drivers/net/ixgbe/ixgbe_ethtool.c
index c19594a..561d478 100644
--- a/drivers/net/ixgbe/ixgbe_ethtool.c
+++ b/drivers/net/ixgbe/ixgbe_ethtool.c
@@ -1975,6 +1975,41 @@ static int ixgbe_get_coalesce(struct net_device *netdev,
 	return 0;
 }
 
+/*
+ * this function must be called before setting the new value of
+ * rx_itr_setting
+ */
+static bool ixgbe_update_rsc(struct ixgbe_adapter *adapter,
+			     struct ethtool_coalesce *ec)
+{
+	struct net_device *netdev = adapter->netdev;
+
+	if (!(adapter->flags2 & IXGBE_FLAG2_RSC_CAPABLE))
+		return false;
+
+	/* if interrupt rate is too high then disable RSC */
+	if (ec->rx_coalesce_usecs != 1 &&
+	    ec->rx_coalesce_usecs <= 1000000/IXGBE_MAX_RSC_INT_RATE) {
+		if (adapter->flags2 & IXGBE_FLAG2_RSC_ENABLED) {
+			e_info(probe, "rx-usecs set too low, "
+				      "disabling RSC\n");
+			adapter->flags2 &= ~IXGBE_FLAG2_RSC_ENABLED;
+			return true;
+		}
+	} else {
+		/* check the feature flag value and enable RSC if necessary */
+		if ((netdev->features & NETIF_F_LRO) &&
+		    !(adapter->flags2 & IXGBE_FLAG2_RSC_ENABLED)) {
+			e_info(probe, "rx-usecs set to %d, "
+				      "re-enabling RSC\n",
+			       ec->rx_coalesce_usecs);
+			adapter->flags2 |= IXGBE_FLAG2_RSC_ENABLED;
+			return true;
+		}
+	}
+	return false;
+}
+
 static int ixgbe_set_coalesce(struct net_device *netdev,
                               struct ethtool_coalesce *ec)
 {
@@ -1992,17 +2027,14 @@ static int ixgbe_set_coalesce(struct net_device *netdev,
 		adapter->tx_ring[0]->work_limit = ec->tx_max_coalesced_frames_irq;
 
 	if (ec->rx_coalesce_usecs > 1) {
-		u32 max_int;
-		if (adapter->flags2 & IXGBE_FLAG2_RSC_ENABLED)
-			max_int = IXGBE_MAX_RSC_INT_RATE;
-		else
-			max_int = IXGBE_MAX_INT_RATE;
-
 		/* check the limits */
-		if ((1000000/ec->rx_coalesce_usecs > max_int) ||
+		if ((1000000/ec->rx_coalesce_usecs > IXGBE_MAX_INT_RATE) ||
 		    (1000000/ec->rx_coalesce_usecs < IXGBE_MIN_INT_RATE))
 			return -EINVAL;
 
+		/* check the old value and enable RSC if necessary */
+		need_reset = ixgbe_update_rsc(adapter, ec);
+
 		/* store the value in ints/second */
 		adapter->rx_eitr_param = 1000000/ec->rx_coalesce_usecs;
 
@@ -2011,32 +2043,21 @@ static int ixgbe_set_coalesce(struct net_device *netdev,
 		/* clear the lower bit as its used for dynamic state */
 		adapter->rx_itr_setting &= ~1;
 	} else if (ec->rx_coalesce_usecs == 1) {
+		/* check the old value and enable RSC if necessary */
+		need_reset = ixgbe_update_rsc(adapter, ec);
+
 		/* 1 means dynamic mode */
 		adapter->rx_eitr_param = 20000;
 		adapter->rx_itr_setting = 1;
 	} else {
+		/* check the old value and enable RSC if necessary */
+		need_reset = ixgbe_update_rsc(adapter, ec);
 		/*
 		 * any other value means disable eitr, which is best
 		 * served by setting the interrupt rate very high
 		 */
 		adapter->rx_eitr_param = IXGBE_MAX_INT_RATE;
 		adapter->rx_itr_setting = 0;
-
-		/*
-		 * if hardware RSC is enabled, disable it when
-		 * setting low latency mode, to avoid errata, assuming
-		 * that when the user set low latency mode they want
-		 * it at the cost of anything else
-		 */
-		if (adapter->flags2 & IXGBE_FLAG2_RSC_ENABLED) {
-			adapter->flags2 &= ~IXGBE_FLAG2_RSC_ENABLED;
-			if (netdev->features & NETIF_F_LRO) {
-				netdev->features &= ~NETIF_F_LRO;
-				e_info(probe, "rx-usecs set to 0, "
-				       "disabling RSC\n");
-			}
-			need_reset = true;
-		}
 	}
 
 	if (ec->tx_coalesce_usecs > 1) {
@@ -2123,15 +2144,15 @@ static int ixgbe_set_flags(struct net_device *netdev, u32 data)
 		return rc;
 
 	/* if state changes we need to update adapter->flags and reset */
-	if (adapter->flags2 & IXGBE_FLAG2_RSC_CAPABLE) {
-		/*
-		 * cast both to bool and verify if they are set the same
-		 * but only enable RSC if itr is non-zero, as
-		 * itr=0 and RSC are mutually exclusive
-		 */
-		if (((!!(data & ETH_FLAG_LRO)) !=
-		     (!!(adapter->flags2 & IXGBE_FLAG2_RSC_ENABLED))) &&
-		    adapter->rx_itr_setting) {
+	if ((adapter->flags2 & IXGBE_FLAG2_RSC_CAPABLE) &&
+	    (!!(data & ETH_FLAG_LRO) !=
+	     !!(adapter->flags2 & IXGBE_FLAG2_RSC_ENABLED))) {
+		if ((data & ETH_FLAG_LRO) &&
+		    (!adapter->rx_itr_setting ||
+		     (adapter->rx_itr_setting > IXGBE_MAX_RSC_INT_RATE))) {
+			e_info(probe, "rx-usecs set too low, "
+				      "not enabling RSC.\n");
+		} else {
 			adapter->flags2 ^= IXGBE_FLAG2_RSC_ENABLED;
 			switch (adapter->hw.mac.type) {
 			case ixgbe_mac_82599EB:
@@ -2140,11 +2161,6 @@ static int ixgbe_set_flags(struct net_device *netdev, u32 data)
 			default:
 				break;
 			}
-		} else if (!adapter->rx_itr_setting) {
-			netdev->features &= ~NETIF_F_LRO;
-			if (data & ETH_FLAG_LRO)
-				e_info(probe, "rx-usecs set to 0, "
-				       "LRO/RSC cannot be enabled.\n");
 		}
 	}