openwrtv4/target/linux/brcm2708/patches-4.4/0158-smsx95xx-Add-option-to-disable-the-crimes-against-tr.patch

From 3bd2928682ee70f260d9c62a17d1a5e43f979fec Mon Sep 17 00:00:00 2001
From: popcornmix <popcornmix@gmail.com>
Date: Wed, 20 Jan 2016 17:50:09 +0000
Subject: [PATCH] smsx95xx: Add option to disable the crimes against truesize
 fix

It may improve iperf numbers on Pi 1, but may generate dmesg warnings and possibly cause network issues
See issue 1248.
---
 drivers/net/usb/smsc95xx.c | 8 ++++++++
 1 file changed, 8 insertions(+)
 mode change 100755 => 100644 drivers/net/usb/smsc95xx.c

--- a/drivers/net/usb/smsc95xx.c
+++ b/drivers/net/usb/smsc95xx.c
@@ -75,6 +75,10 @@ static bool turbo_mode = false;
 module_param(turbo_mode, bool, 0644);
 MODULE_PARM_DESC(turbo_mode, "Enable multiple frames per Rx transaction");
 
+static bool truesize_mode = false;
+module_param(truesize_mode, bool, 0644);
+MODULE_PARM_DESC(truesize_mode, "Report larger truesize value");
+
 static char *macaddr = ":";
 module_param(macaddr, charp, 0);
 MODULE_PARM_DESC(macaddr, "MAC address");
@@ -1841,6 +1845,8 @@ static int smsc95xx_rx_fixup(struct usbn
 				if (dev->net->features & NETIF_F_RXCSUM)
 					smsc95xx_rx_csum_offload(skb);
 				skb_trim(skb, skb->len - 4); /* remove fcs */
+				if (truesize_mode)
+					skb->truesize = size + sizeof(struct sk_buff);
 
 				return 1;
 			}
@@ -1858,6 +1864,8 @@ static int smsc95xx_rx_fixup(struct usbn
 			if (dev->net->features & NETIF_F_RXCSUM)
 				smsc95xx_rx_csum_offload(ax_skb);
 			skb_trim(ax_skb, ax_skb->len - 4); /* remove fcs */
+			if (truesize_mode)
+				ax_skb->truesize = size + sizeof(struct sk_buff);
 
 			usbnet_skb_return(dev, ax_skb);
 		}