igb: A fix to VF TX rate limit

There is a need to configure MMW_SIZE in register RTTBCNRM with a correct
value. For 82576 device, the value should be 0x14.

Signed-off-by: Lior Levy <lior.levy@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index dd3bfe8..6409054 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -6997,6 +6997,11 @@
 	}
 
 	wr32(E1000_RTTDQSEL, vf); /* vf X uses queue X */
+	/*
+	 * Set global transmit compensation time to the MMW_SIZE in RTTBCNRM
+	 * register. MMW_SIZE=0x014 if 9728-byte jumbo is supported.
+	 */
+	wr32(E1000_RTTBCNRM, 0x14);
 	wr32(E1000_RTTBCNRC, bcnrc_val);
 }