On Thu, 14 Apr 2016, Alan Stern wrote: > On Thu, 14 Apr 2016, Matthew Giassa wrote: > > > Replying in-line: > > > > > > You are correct: the software claims and releases certain interfaces > > > > frequently. > > > > > > How frequently? The usbmon log you attached to the Bugzilla report > > > shows it happening at intervals of approximately 20-40 ms (sometimes > > > longer) -- and often with no messages sent in between. Does that seem > > > at all reasonable? > > That polling interval you describe is the extreme case, but its not that > > uncommon. It just depends what "metrics" are enabled by the "gathering" > > thread. The case of no messages being passed does not seem reasonable. > > Data is expected to be transferred between each claim/release. > > You should track that down; it sounds like a bug in your program. My mistake. The kernel is responsible for this, not your program. For each claim_interface it disables and then enables LPM, and the same for each release_interface. That explains (partly) the pattern of activity seen in the usbmon trace. 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
