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authorMing Lei <ming.lei@canonical.com>2013-08-08 13:48:25 (GMT)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-08-12 19:09:51 (GMT)
commit3804fad45411b48233b48003e33a78f290d227c8 (patch)
tree65ab2947e744b36ed2c8f357b7fde992b9c54d16 /drivers/net/usb
parent638c5115a794981441246fa8fa5d95c1875af5ba (diff)
downloadlinux-3804fad45411b48233b48003e33a78f290d227c8.tar.xz
USBNET: ax88179_178a: enable tso if usb host supports sg dma
This patch enables 'can_dma_sg' flag for ax88179_178a device if the attached host controller supports building packet from discontinuous buffers(DMA SG is possible), so TSO can be enabled and skb fragment buffers can be passed to usb stack via urb->sg directly. With the patch, system CPU utilization decreased ~50% and throughput increased by ~10% when doing iperf client test on one ARM A15 dual core board. Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Grant Grundler <grundler@google.com> Cc: Oliver Neukum <oneukum@suse.de> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Freddy Xin <freddy@asix.com.tw> Signed-off-by: Ming Lei <ming.lei@canonical.com> Acked-by: Eric Dumazet <edumazet@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/net/usb')
-rw-r--r--drivers/net/usb/ax88179_178a.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
index 2bc87e3..4233c05 100644
--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c
@@ -1028,12 +1028,20 @@ static int ax88179_bind(struct usbnet *dev, struct usb_interface *intf)
dev->mii.phy_id = 0x03;
dev->mii.supports_gmii = 1;
+ if (usb_device_no_sg_constraint(dev->udev))
+ dev->can_dma_sg = 1;
+
dev->net->features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
NETIF_F_RXCSUM;
dev->net->hw_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
NETIF_F_RXCSUM;
+ if (dev->can_dma_sg) {
+ dev->net->features |= NETIF_F_SG | NETIF_F_TSO;
+ dev->net->hw_features |= NETIF_F_SG | NETIF_F_TSO;
+ }
+
/* Enable checksum offload */
*tmp = AX_RXCOE_IP | AX_RXCOE_TCP | AX_RXCOE_UDP |
AX_RXCOE_TCPV6 | AX_RXCOE_UDPV6;