Many of the net/usb ethernet drivers (including common ones like the smsc95xx) will fail to transmit all packet length properly when connected to a USB3 port (ie using the xhci driver). The underlying problem is that they assume the host controller will honour the URB_ZERO_PACKET flag - which usbnet sets because they specify FLAG_SEND_ZLP. However no one has ever added support for URB_ZERO_PACKET to the xhci driver - so packets that need padding (probably 512 bytes after any header is added) will not be sent correctly and may have very adverse effects on the usb target. The ax179_178a driver avoids this by not setting FLAG_SEND_ZLP, modifying the packet header, and appending an extra zero byte. (Which has been responsible for its own set of panics.) I don't think this can be fixed by just clearing (or ignoring) FLAG_SEND_ZLP as the extra byte will also confuse things. It needs to be fixed in the xhci code. I wrote this patch a while ago - worked for me with the ax179_178a driver. http://www.spinics.net/lists/linux-usb/msg97370.html The patch is a bit difficult to read, the v1 version contained a copy of the new function. http://www.spinics.net/lists/linux-usb/msg97183.html I don't think anything significant has changed (in the main kernel sources) since I wrote the patch. David -- 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
