Fons Adriaensen wrote: >On Sat, Dec 31, 2016 at 07:10:16AM +0100, Clemens Ladisch wrote: >> The two data lines (D+ and D-) have controlled impedances and drive >> levels so that the effective currents are symmetrical, but when both >> lines are pulled low to signal EOP, there is not necessarily an equivalent >> return current over the ground line. > >There must be. The net sum of the currents flowing through he cable >must be zero, unless some current takes a path (e.g. via protective >ground) not going via the cable. > >If two devices are connected only by the USB cable there is no >such path. Indeed. But if the device is _not_ bus powered, there is such a path. Regards, Clemens _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
