On Thu, Feb 06, 2014 at 03:39:02PM +0000, David Laight wrote: > From: Daniel J Blueman > > Hi Freddy et al, > > I've copied this to linux-usb. > > > I'm experiencing poor network performance using an ASIX AX88179_178A > > USB3 to ethernet adapter using any recent linux kernel (eg 3.11), > > using an Intel XHCI USB3 controller. > > There a several problems with the xhci driver that show up when > trying to use the ax88179_178a driver. > Unfortunately some of the fixes have caused regressions on other > host controllers with disk transfers. > The patches may, or may not, be present in your kernel. > The 'scatter-gather' support that is used in order to enable TSO > is particularly good at exercising the buggy code paths. Scatter gather was not added until 3.12. That does not explain the issues with a 3.11 kernel. (Unless we're hitting the 64-KB boundary corner case a lot in 3.11.) > > Running iperf tests between one host with a gigabit PCIe NIC, via a > > gigabit switch to the other host with various interfaces: > > > > PCIe bcm957762: send 818Mb/s, recv 910Mb/s > > USB2 smsc75xx: send 341Mb/s, recv 330Mb/s > > USB3 ax88179_178a: send 347Mb/s, recv 18.7Mb/s > > > > Are you able to reproduce the same 19Mb/s receive rate there? Which kernel are these numbers for? Any chance you can test this adapter on Windows? I would be interested to see whether the send and recv numbers are also asymmetrical there. > It might be that you are only actually running at USB2 speeds > (check with lsusb -t). > > I have seem line rate Ge from my ax88179 card, but only with a > patched kernel. David, did you mean you have the same line rate as Daniel? Sarah Sharp -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
