diff --git a/drivers/net/ethernet/chelsio/cxgb4vf/t4vf_defs.h b/drivers/net/ethernet/chelsio/cxgb4vf/t4vf_defs.h
index b516b12b188459eabf2397f7dcdbfb17279c7a48..f859db3d254cd27527287dca95f9c7d1d3512493 100644
--- a/drivers/net/ethernet/chelsio/cxgb4vf/t4vf_defs.h
+++ b/drivers/net/ethernet/chelsio/cxgb4vf/t4vf_defs.h
@@ -54,6 +54,7 @@
 #define T4VF_MPS_BASE_ADDR	0x0100
 #define T4VF_PL_BASE_ADDR	0x0200
 #define T4VF_MBDATA_BASE_ADDR	0x0240
+#define T6VF_MBDATA_BASE_ADDR	0x0280
 #define T4VF_CIM_BASE_ADDR	0x0300
 
 #define T4VF_REGMAP_START	0x0000
diff --git a/drivers/net/ethernet/chelsio/cxgb4vf/t4vf_hw.c b/drivers/net/ethernet/chelsio/cxgb4vf/t4vf_hw.c
index 63dd5fdac5b91a5ba0186961a395d67f2c5cc7b2..b6fa74aafe4771246baf16af218d6a5c7e54670a 100644
--- a/drivers/net/ethernet/chelsio/cxgb4vf/t4vf_hw.c
+++ b/drivers/net/ethernet/chelsio/cxgb4vf/t4vf_hw.c
@@ -120,12 +120,19 @@ int t4vf_wr_mbox_core(struct adapter *adapter, const void *cmd, int size,
 		1, 1, 3, 5, 10, 10, 20, 50, 100
 	};
 
-	u32 v;
+	u32 v, mbox_data;
 	int i, ms, delay_idx;
 	const __be64 *p;
-	u32 mbox_data = T4VF_MBDATA_BASE_ADDR;
 	u32 mbox_ctl = T4VF_CIM_BASE_ADDR + CIM_VF_EXT_MAILBOX_CTRL;
 
+	/* In T6, mailbox size is changed to 128 bytes to avoid
+	 * invalidating the entire prefetch buffer.
+	 */
+	if (CHELSIO_CHIP_VERSION(adapter->params.chip) <= CHELSIO_T5)
+		mbox_data = T4VF_MBDATA_BASE_ADDR;
+	else
+		mbox_data = T6VF_MBDATA_BASE_ADDR;
+
 	/*
 	 * Commands must be multiples of 16 bytes in length and may not be
 	 * larger than the size of the Mailbox Data register array.