On Mon, 16 Jan 2012, Sarah Sharp wrote: > > That's a good question. In general, inner nodes should have very short > > delays. > > > > On the other hand, USB hubs aren't always inner nodes. They generate > > their own wake requests, in addition to forwarding requests from > > downstream. Therefore hubs should not necessarily have short delays. > > Sorry, I still don't get it. :) Why can't we immediately suspend a > parent hub when all its children are suspended? I don't see why the > fact that the hub may send remote wake events for device > connect/disconnect should have any effect on how fast we suspend the > hub. Maybe we can do it. I haven't experimented very much with this, but it's easy enough to do with USB-2 hubs. Just set the autosuspend delay to 0. (One can make a good case that the usb_mark_last_busy() calls don't belong in the usb_autopm_put_interface_* routines. That's a separate question.) 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
