[PATCH] net: usb: ax88179_178a: add TSO feature

Jacky Chou
2021-11-12T03:39:48Z

On low-effciency embedded platforms, transmission performance is poor
due to on Bulk-out with single packet.
Adding TSO feature improves the transmission performance and reduces
the number of interrupt caused by Bulk-out complete.

Reference to module, net: usb: aqc111.

Signed-off-by: Jacky Chou <jackychou@asix.com.tw>
---
drivers/net/usb/ax88179_178a.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
index c13167183..866954155 100644
--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c
@@ -1368,6 +1368,9 @@ static int ax88179_bind(struct usbnet *dev, struct usb_interface *intf)
dev->net->needed_headroom = 8;
dev->net->max_mtu = 4088;

+ if (usb_device_no_sg_constraint(dev->udev))
+ dev->can_dma_sg = 1;
+
/* Initialize MII structure */
dev->mii.dev = dev->net;
dev->mii.mdio_read = ax88179_mdio_read;
@@ -1377,11 +1380,14 @@ static int ax88179_bind(struct usbnet *dev, struct usb_interface *intf)
dev->mii.phy_id = 0x03;
dev->mii.supports_gmii = 1;

- dev->net->features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
- NETIF_F_RXCSUM;
+ dev->net->features |= NETIF_F_SG | NETIF_F_IP_CSUM |
+ NETIF_F_IPV6_CSUM | NETIF_F_RXCSUM | NETIF_F_TSO;

- dev->net->hw_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
- NETIF_F_RXCSUM;
+ dev->net->hw_features |= NETIF_F_SG | NETIF_F_IP_CSUM |
+ NETIF_F_IPV6_CSUM | NETIF_F_RXCSUM |
+ NETIF_F_TSO;
+
+ netif_set_gso_max_size(dev->net, 16384);

/* Enable checksum offload */
*tmp = AX_RXCOE_IP | AX_RXCOE_TCP | AX_RXCOE_UDP |
@@ -1537,6 +1543,10 @@ ax88179_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)

headroom = skb_headroom(skb) - 8;

+ if (!dev->can_dma_sg && (dev->net->features & NETIF_F_SG) &&
+ skb_linearize(skb))
+ return NULL;
+
if ((skb_header_cloned(skb) || headroom < 0) &&
pskb_expand_head(skb, headroom < 0 ? 8 : 0, 0, GFP_ATOMIC)) {
dev_kfree_skb_any(skb);
--
2.25.1