On Tue, 2013-08-06 at 08:52 +0800, Ming Lei wrote:
> 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.
>
Nice ;)
> 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;
> + }
>
My concern with setting TSO on reset() is the following :
Admin can disable TSO with
ethtool -K ethX tso off
Then, one hour later, or one month later, a reset happens, and this code
magically re-enables TSO
So, I really think this part should be removed from your patch.
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