fm10k: don't reinitialize RSS flow table when RXFH configured

BugLink: http://bugs.launchpad.net/bugs/1562310

Also print an error message incase we do have to reconfigure as this
should no longer happen anymore due to ethtool changes. If it somehow
does occur, user should be made aware of it.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 1012014e)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

drivers/net/ethernet/intel/fm10k/fm10k_main.c

@@ -1937,8 +1937,10 @@ static void fm10k_init_reta(struct fm10k_intfc *interface)
 	u16 i, rss_i = interface->ring_feature[RING_F_RSS].indices;
 	u32 reta, base;
 
-	/* If the netdev is initialized we have to maintain table if possible */
-	if (interface->netdev->reg_state != NETREG_UNINITIALIZED) {
+	/* If the Rx flow indirection table has been configured manually, we
+	 * need to maintain it when possible.
+	 */
+	if (netif_is_rxfh_configured(interface->netdev)) {
 		for (i = FM10K_RETA_SIZE; i--;) {
 			reta = interface->reta[i];
 			if ((((reta << 24) >> 24) < rss_i) &&
@@ -1946,6 +1948,10 @@ static void fm10k_init_reta(struct fm10k_intfc *interface)
 			    (((reta <<  8) >> 24) < rss_i) &&
 			    (((reta)       >> 24) < rss_i))
 				continue;
+
+			/* this should never happen */
+			dev_err(&interface->pdev->dev,
+				"RSS indirection table assigned flows out of queue bounds. Reconfiguring.\n");
 			goto repopulate_reta;
 		}