[PATCH] e1000: The user-supplied itr setting needs the lower 2 bits masked off

The lower 2 bits of a user-supplied itr setting (via ethtool) need to be
masked off: These lower two bits are used as control bits.
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: NAuke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

drivers/net/e1000/e1000_param.c

@@ -487,7 +487,9 @@ e1000_check_options(struct e1000_adapter *adapter)
 				e1000_validate_option(&adapter->itr, &opt,
 				        adapter);
 				/* save the setting, because the dynamic bits change itr */
-				adapter->itr_setting = adapter->itr;
+				/* clear the lower two bits because they are
+				 * used as control */
+				adapter->itr_setting = adapter->itr & ~3;
 				break;
 			}
 		} else {