On Fri, 3 Aug 2012, mat brown wrote: > Already done as requested by the Ubuntu devs. File is here: > https://launchpadlibrarian.net/111697628/usbmon.out > > The transfer which created that file was generated using dd > if=/dev/zero of=/media/littlun/tmp oflag=direct bs=120K count=2K It's odd. The usbmon log shows things working pretty well most of the time, with transfer speeds around 200 Mb/s, but every now and then a single 120-KB transfer takes more than half a second! I have no idea why. We can rule out hardware problems because it doesn't happen under Fedora. Maybe interrupt delivery gets delayed somehow under Ubuntu, or maybe something is different in the xhci-hcd driver. Can you compare the driver source files? To do more serious testing will require you to build your own kernel, or at least, your own version of the driver. Alan Stern -- 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
