From 6b8456c0199c4dd35bb7a04ff299ab925699e390 Mon Sep 17 00:00:00 2001
From: John Fastabend <john.r.fastabend@intel.com>
Date: Wed, 21 Sep 2011 14:44:10 +0000
Subject: [PATCH] ixgbe: X540 devices RX PFC frames pause traffic even if
 disabled

Receiving PFC (priority flow control) frames while the feature
is off should not pause the traffic class. On the X540 devices
the traffic class react to frames if it was previously enabled
because the field is incorrectly cleared.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_dcb_82599.c | 12 +++++++++++-
 drivers/net/ethernet/intel/ixgbe/ixgbe_type.h      |  2 +-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_dcb_82599.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_dcb_82599.c
index 45fe71030455..32cd97bc794d 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_dcb_82599.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_dcb_82599.c
@@ -271,13 +271,23 @@ s32 ixgbe_dcb_config_pfc_82599(struct ixgbe_hw *hw, u8 pfc_en, u8 *prio_tc)
 		reg |= IXGBE_MFLCN_RPFCE | IXGBE_MFLCN_DPF;
 
 		if (hw->mac.type == ixgbe_mac_X540) {
-			reg &= ~(IXGBE_MFLCN_RPFCE_MASK | 0x10);
+			reg &= ~IXGBE_MFLCN_RPFCE_MASK;
 			reg |= pfc_en << IXGBE_MFLCN_RPFCE_SHIFT;
 		}
 
 		IXGBE_WRITE_REG(hw, IXGBE_MFLCN, reg);
 
 	} else {
+		/* X540 devices have a RX bit that should be cleared
+		 * if PFC is disabled on all TCs but PFC features is
+		 * enabled.
+		 */
+		if (hw->mac.type == ixgbe_mac_X540) {
+			reg = IXGBE_READ_REG(hw, IXGBE_MFLCN);
+			reg &= ~IXGBE_MFLCN_RPFCE_MASK;
+			IXGBE_WRITE_REG(hw, IXGBE_MFLCN, reg);
+		}
+
 		for (i = 0; i < MAX_TRAFFIC_CLASS; i++)
 			hw->mac.ops.fc_enable(hw, i);
 	}
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h b/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
index 4ea909c7951b..d1d689471523 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
@@ -1850,7 +1850,7 @@ enum {
 #define IXGBE_MFLCN_DPF         0x00000002 /* Discard Pause Frame */
 #define IXGBE_MFLCN_RPFCE       0x00000004 /* Receive Priority FC Enable */
 #define IXGBE_MFLCN_RFCE        0x00000008 /* Receive FC Enable */
-#define IXGBE_MFLCN_RPFCE_MASK	0x00000FE0 /* Receive FC Mask */
+#define IXGBE_MFLCN_RPFCE_MASK	0x00000FF0 /* Receive FC Mask */
 
 #define IXGBE_MFLCN_RPFCE_SHIFT		 4
 
-- 
2.30.9