usbnet: do not pretend to support SG/TSO

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@asix.com.tw>

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
index 1e3c302d94fe338dec36ba934fc90a79bfb00e0d..2bc87e3a8141d259502bcfbfccc9e0a5b649800b 100644 (file)
--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c
@@ -1029,10 +1029,10 @@ static int ax88179_bind(struct usbnet *dev, struct usb_interface *intf)
        dev->mii.supports_gmii = 1;
 
        dev->net->features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
-                             NETIF_F_RXCSUM | NETIF_F_SG | NETIF_F_TSO;
+                             NETIF_F_RXCSUM;
 
        dev->net->hw_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
-                                NETIF_F_RXCSUM | NETIF_F_SG | NETIF_F_TSO;
+                                NETIF_F_RXCSUM;
 
        /* Enable checksum offload */
        *tmp = AX_RXCOE_IP | AX_RXCOE_TCP | AX_RXCOE_UDP |
@@ -1173,7 +1173,6 @@ ax88179_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
        if (((skb->len + 8) % frame_size) == 0)
                tx_hdr2 |= 0x80008000;  /* Enable padding */
 
-       skb_linearize(skb);
        headroom = skb_headroom(skb);
        tailroom = skb_tailroom(skb);
 
@@ -1317,10 +1316,10 @@ static int ax88179_reset(struct usbnet *dev)
                          1, 1, tmp);
 
        dev->net->features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
-                             NETIF_F_RXCSUM | NETIF_F_SG | NETIF_F_TSO;
+                             NETIF_F_RXCSUM;
 
        dev->net->hw_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
-                                NETIF_F_RXCSUM | NETIF_F_SG | NETIF_F_TSO;
+                                NETIF_F_RXCSUM;
 
        /* Enable checksum offload */
        *tmp = AX_RXCOE_IP | AX_RXCOE_TCP | AX_RXCOE_UDP |

diff --git a/drivers/net/usb/smsc75xx.c b/drivers/net/usb/smsc75xx.c
index 75409748c77470da8cc5bcc7390e9f4c5a94ea6a..66ebbacf066f6692ba21d2fa07538535827074b9 100644 (file)
--- a/drivers/net/usb/smsc75xx.c
+++ b/drivers/net/usb/smsc75xx.c
@@ -45,7 +45,6 @@
 #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)
@@ -1410,17 +1409,14 @@ static int smsc75xx_bind(struct usbnet *dev, struct usb_interface *intf)
 
        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;
 
        ret = smsc75xx_wait_ready(dev, 0);
        if (ret < 0) {
@@ -2200,8 +2196,6 @@ static struct sk_buff *smsc75xx_tx_fixup(struct usbnet *dev,
 {
        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);