Hi, On Mon, Jan 25, 2016 at 1:51 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > 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. What analyzer are you using? -Doug -- 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
