On Sun, 5 Jul 2015, Andy Furniss wrote: > Alan Stern wrote: > > >> Is 0u the wrong thing to do? > > > > It depends on what you want. If you want complete details (all the > > packets, all the data) then you need to use the binary interface, > > i.e., wireshark or dumpcap. > > > > But if it helps to know that roughly one packet in every four is > > received with length 0 (or possibly is not received at all), then > > maybe your usbmon capture has served a useful purpose. > > Thanks for looking - for this mux on average I would expect 42 (188) > packets per 64 x 940 "line" and though rare I see sometimes there can be > more than one (x188) in a 940 usb packet. > > I know I only lost 13 packets out if 1.7 million - I was hoping there > may be some way to see why or if in fact they were missing from the > usbmon dump. > > I am kicking my self now though, I had some time ago downloaded an app > called usbmon and if I use that I see it shows the real data length per > line rather than 60160 - so I could have just totted up to see if it > matched the recording. Of course if it uses too much CPU to do this it > will be no use as I won't get any loss! > > Next time I get some time (and no one needs the internet as it's also my > router) to put a monitor back on the problem board I will try again - > xhci is disabled again in bios as using ehci is almost a 100% workaround > for me. I did try building xhci as a module in the hope of easier > testing but I still didn't get ehci for the usb2 ports. Another possibility, if you can figure out a good way to describe what you're looking for, it to manually add some testing and logging to one of the kernel drivers. I don't know what you would test for, though. 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
