redonkable/remarkable-linux
redonkable/remarkable-linux
1
0
Fork 0
Code Releases Activity

USBNET: ax88179_178a: enable tso if usb host supports sg dma

Browse source 
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>
This commit is contained in:
Ming Lei 2013-08-08 21:48:25 +08:00 committed by Greg Kroah-Hartman
parent 638c5115a7
commit 3804fad454
1 changed files with 8 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
drivers/net/usb/ax88179_178a.c
View file

@ -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;