On Wed, 1 Feb 2012, Sarah Sharp wrote: > > > accept the U3 transition, but immediately initiate resume signaling. > > > The hub shall initiate a resume regardless of whether it has been > > > enabled for remote wakeup. The hub shall not send a Function Wake > > > Device Notification, but instead shall rely on the device to send it. > > > > "the device" above is ambiguous; you can simply omit the second half > > of that sentence. > > > > Are you sure you don't want the hub to send a notification? It seems > > to me that this just repeats the mistake made in the original spec: A > > USB device changes a link state away from U3 without anyone telling the > > host about it. What if the downstream device never does send its > > notification? > > The device continues to send Function Wake notifications every > tNotification (2.5 seconds) if it has not been accessed after it sent > the first notification. So we will eventually see it. ... if the device is working properly. What if it isn't? If a device fails to send notifications as it should, the host won't learn when the device does a wakeup. If the hub also doesn't send notifications, the host won't learn that the hub has woken up either. This sort of thing shouldn't happen when the hub is working properly -- even if the device is broken. 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
