On Mon, 25 Jan 2016, Peter Stuge wrote: > Alan Stern wrote: > > the device's embedded hub ACKs the packets from the PC and not the > > packets from the RPi. > > > > What other differences could there be? Timing? Power levels? > > Yes, both good candidates. Can you measure VUSB? Distinctly higher than 5V. > As for timing, the > host controller will send SOF more or less regularly, if too > irregular then that could cause problems for the device. Does your > analyzer provide precise timestamps? Yes, but the software doesn't want to display individual SOF packets. However I can see, for example, that 84 SOF packets were sent during a 10.3-ms period. Or 2048 were sent during a 256-ms period. It seems pretty regular. 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
