[PATCH v3 4/4] USBNET: ax88179_178a: enable tso if usb host supports sg dma
From: Ming Lei <hidden>
Date: 2013-08-06 00:53:51
Subsystem:
networking drivers, the rest, usb networking drivers · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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: Eric Dumazet <redacted> Cc: Ben Hutchings <redacted> Cc: Grant Grundler <redacted> Cc: Oliver Neukum <redacted> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Freddy Xin <redacted> Signed-off-by: Ming Lei <redacted> --- drivers/net/usb/ax88179_178a.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
index fb0caa2..7a96326 100644
--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c@@ -1031,12 +1031,20 @@ 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;
@@ -1310,6 +1318,10 @@ static int ax88179_reset(struct usbnet *dev) 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 |
--
1.7.9.5