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 1e3c302..2bc87e3 100644
--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c
@@ -1029,10 +1029,10 @@
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 @@
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 @@
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 7540974..66ebbac 100644
--- 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 @@
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 @@
{
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);