Patch "usbnet: do not pretend to support SG/TSO" has been added to the 3.4-stable tree

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This is a note to let you know that I've just added the patch titled

    usbnet: do not pretend to support SG/TSO

to the 3.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     usbnet-do-not-pretend-to-support-sg-tso.patch
and it can be found in the queue-3.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.


>From 9ee50cf7b0ac02b2c615517e1bacd6b8cbdcb7ea Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Tue, 23 Jul 2013 17:15:54 -0700
Subject: usbnet: do not pretend to support SG/TSO

From: Eric Dumazet <edumazet@xxxxxxxxxx>

[ Upstream commit 20f0170377264e8449b6987041f0bcc4d746d3ed ]

usbnet doesn't support yet SG, so drivers should not advertise SG or TSO
capabilities, as they allow TCP stack to build large TSO packets that
need to be linearized and might use order-5 pages.

This adds an extra copy overhead and possible allocation failures.

Current code ignore skb_linearize() return code so crashes are even
possible.

Best is to not pretend SG/TSO is supported, and add this again when/if
usbnet really supports SG for devices who could get a performance gain.

Based on a prior patch from Freddy Xin <freddy@xxxxxxxxxxx>

Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/usb/smsc75xx.c |   12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

--- a/drivers/net/usb/smsc75xx.c
+++ b/drivers/net/usb/smsc75xx.c
@@ -43,7 +43,6 @@
 #define EEPROM_MAC_OFFSET		(0x01)
 #define DEFAULT_TX_CSUM_ENABLE		(true)
 #define DEFAULT_RX_CSUM_ENABLE		(true)
-#define DEFAULT_TSO_ENABLE		(true)
 #define SMSC75XX_INTERNAL_PHY_ID	(1)
 #define SMSC75XX_TX_OVERHEAD		(8)
 #define MAX_RX_FIFO_SIZE		(20 * 1024)
@@ -1049,17 +1048,14 @@ static int smsc75xx_bind(struct usbnet *
 
 	INIT_WORK(&pdata->set_multicast, smsc75xx_deferred_multicast_write);
 
-	if (DEFAULT_TX_CSUM_ENABLE) {
+	if (DEFAULT_TX_CSUM_ENABLE)
 		dev->net->features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
-		if (DEFAULT_TSO_ENABLE)
-			dev->net->features |= NETIF_F_SG |
-				NETIF_F_TSO | NETIF_F_TSO6;
-	}
+
 	if (DEFAULT_RX_CSUM_ENABLE)
 		dev->net->features |= NETIF_F_RXCSUM;
 
 	dev->net->hw_features = NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
-		NETIF_F_SG | NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_RXCSUM;
+				NETIF_F_RXCSUM;
 
 	/* Init all registers */
 	ret = smsc75xx_reset(dev);
@@ -1184,8 +1180,6 @@ static struct sk_buff *smsc75xx_tx_fixup
 {
 	u32 tx_cmd_a, tx_cmd_b;
 
-	skb_linearize(skb);
-
 	if (skb_headroom(skb) < SMSC75XX_TX_OVERHEAD) {
 		struct sk_buff *skb2 =
 			skb_copy_expand(skb, SMSC75XX_TX_OVERHEAD, 0, flags);


Patches currently in stable-queue which might be from edumazet@xxxxxxxxxx are

queue-3.4/usbnet-do-not-pretend-to-support-sg-tso.patch
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