diff mbox series

net: usb: ax88179_178a: add TSO feature

Message ID 20211112033322.741974-1-jackychou@asix.com.tw (mailing list archive)
State Superseded
Headers show
Series net: usb: ax88179_178a: add TSO feature | expand

Commit Message

Jacky Chou Nov. 12, 2021, 3:33 a.m. UTC
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(-)

Comments

Jakub Kicinski Nov. 13, 2021, 3:47 a.m. UTC | #1
On Fri, 12 Nov 2021 11:33:22 +0800 Jacky Chou wrote:
> 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;

Why don't you use this information...

>  	/* 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;

... to conditionally set the NETIF_F_SG flag?

> -	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;

If you want to enable all the features just write:

	dev->net->hw_features |= dev->net->features;

No need to repeat all the flags.

> +	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);

Okay... where is the TSO implementation? The TCP stack passes
parameters like MSS which you need to inform the device about.
You should also count TSO packets as multiple packets in stats.

Are you sure this device supports TSO and not just SG?
diff mbox series

Patch

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);