From 9c0827317f235865ae421293f8aecf6cb327a63e Mon Sep 17 00:00:00 2001
From: Nisar Sayed <Nisar.Sayed@microchip.com>
Date: Mon, 11 Sep 2017 17:43:11 +0000
Subject: [PATCH] smsc95xx: Configure pause time to 0xffff when tx flow control enabled
Git-commit: 9c0827317f235865ae421293f8aecf6cb327a63e
Patch-mainline: v4.14-rc1
References: bsc#1051510

Configure pause time to 0xffff when tx flow control enabled

Set pause time to 0xffff in the pause frame to indicate the
partner to stop sending the packets. When RX buffer frees up,
the device sends pause frame with pause time zero for partner to
resume transmission.

Fixes: 2f7ca802bdae ("Add SMSC LAN9500 USB2.0 10/100 ethernet adapter driver")
Signed-off-by: Nisar Sayed <Nisar.Sayed@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/usb/smsc95xx.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c
index 340c13484e5c..309b88acd3d0 100644
--- a/drivers/net/usb/smsc95xx.c
+++ b/drivers/net/usb/smsc95xx.c
@@ -526,7 +526,7 @@ static void smsc95xx_set_multicast(struct net_device *netdev)
 static int smsc95xx_phy_update_flowcontrol(struct usbnet *dev, u8 duplex,
 					   u16 lcladv, u16 rmtadv)
 {
-	u32 flow, afc_cfg = 0;
+	u32 flow = 0, afc_cfg;
 
 	int ret = smsc95xx_read_reg(dev, AFC_CFG, &afc_cfg);
 	if (ret < 0)
@@ -537,20 +537,19 @@ static int smsc95xx_phy_update_flowcontrol(struct usbnet *dev, u8 duplex,
 
 		if (cap & FLOW_CTRL_RX)
 			flow = 0xFFFF0002;
-		else
-			flow = 0;
 
-		if (cap & FLOW_CTRL_TX)
+		if (cap & FLOW_CTRL_TX) {
 			afc_cfg |= 0xF;
-		else
+			flow |= 0xFFFF0000;
+		} else {
 			afc_cfg &= ~0xF;
+		}
 
 		netif_dbg(dev, link, dev->net, "rx pause %s, tx pause %s\n",
 				   cap & FLOW_CTRL_RX ? "enabled" : "disabled",
 				   cap & FLOW_CTRL_TX ? "enabled" : "disabled");
 	} else {
 		netif_dbg(dev, link, dev->net, "half duplex\n");
-		flow = 0;
 		afc_cfg |= 0xF;
 	}
 
-- 
2.18.0