Hi, On Tue, Jan 26, 2016 at 7:08 AM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Mon, 25 Jan 2016, Doug Anderson wrote: > >> 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? > > The Total Phase Beagle 480, with their Data Center analysis software. Hrm. I've got the Beagle 5000 Superspeed on my desk. I can get it to show me individual SOFs, but maybe that's a feature of the new hardware? I'm using Data Center v6.63.000 I had to turn on lots of stuff to see all this and it eats up lots of memory quickly, but it works. I've got: Capture Settings, USB -> Sequential -> Keep USB 2.0 Data-less Sequences In device settings I make sure it's not Filtering anything... -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
