ixgbe: fix bug when EITR=0 causing no writebacks
writebacks can be held indefinitely by hardware if EITR=0, when
combined with TXDCTL.WTHRESH=8. When EITR=0, WTHRESH should be
set back to zero.
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ixgbe/ixgbe_ethtool.c b/drivers/net/ixgbe/ixgbe_ethtool.c
index 1ae0201..5f8c6ab 100644
--- a/drivers/net/ixgbe/ixgbe_ethtool.c
+++ b/drivers/net/ixgbe/ixgbe_ethtool.c
@@ -2083,7 +2083,7 @@
* this function must be called before setting the new value of
* rx_itr_setting
*/
-static void ixgbe_reenable_rsc(struct ixgbe_adapter *adapter,
+static bool ixgbe_reenable_rsc(struct ixgbe_adapter *adapter,
struct ethtool_coalesce *ec)
{
/* check the old value and enable RSC if necessary */
@@ -2093,11 +2093,9 @@
adapter->netdev->features |= NETIF_F_LRO;
DPRINTK(PROBE, INFO, "rx-usecs set to %d, re-enabling RSC\n",
ec->rx_coalesce_usecs);
- if (netif_running(adapter->netdev))
- ixgbe_reinit_locked(adapter);
- else
- ixgbe_reset(adapter);
+ return true;
}
+ return false;
}
static int ixgbe_set_coalesce(struct net_device *netdev,
@@ -2106,6 +2104,7 @@
struct ixgbe_adapter *adapter = netdev_priv(netdev);
struct ixgbe_q_vector *q_vector;
int i;
+ bool need_reset = false;
/* don't accept tx specific changes if we've got mixed RxTx vectors */
if (adapter->q_vector[0]->txr_count && adapter->q_vector[0]->rxr_count
@@ -2128,7 +2127,7 @@
return -EINVAL;
/* check the old value and enable RSC if necessary */
- ixgbe_reenable_rsc(adapter, ec);
+ need_reset = ixgbe_reenable_rsc(adapter, ec);
/* store the value in ints/second */
adapter->rx_eitr_param = 1000000/ec->rx_coalesce_usecs;
@@ -2139,7 +2138,7 @@
adapter->rx_itr_setting &= ~1;
} else if (ec->rx_coalesce_usecs == 1) {
/* check the old value and enable RSC if necessary */
- ixgbe_reenable_rsc(adapter, ec);
+ need_reset = ixgbe_reenable_rsc(adapter, ec);
/* 1 means dynamic mode */
adapter->rx_eitr_param = 20000;
@@ -2164,11 +2163,7 @@
DPRINTK(PROBE, INFO,
"rx-usecs set to 0, disabling RSC\n");
- if (netif_running(netdev))
- ixgbe_reinit_locked(adapter);
- else
- ixgbe_reset(adapter);
- return 0;
+ need_reset = true;
}
}
@@ -2220,6 +2215,18 @@
ixgbe_write_eitr(q_vector);
}
+ /*
+ * do reset here at the end to make sure EITR==0 case is handled
+ * correctly w.r.t stopping tx, and changing TXDCTL.WTHRESH settings
+ * also locks in RSC enable/disable which requires reset
+ */
+ if (need_reset) {
+ if (netif_running(netdev))
+ ixgbe_reinit_locked(adapter);
+ else
+ ixgbe_reset(adapter);
+ }
+
return 0;
}