On Tue, 27 Nov 2012, Sarah Sharp wrote: > Do I need to stop the polling when the host controller is suspended and > restart it when it's resumed? It seems like OHCI does that, but I can't > tell if it's host-specific. Or will the USB core just take care of > stopping and restarting the hub timer? It is driver-specific. (For example, under certain rare conditions uhci-hcd needs to poll for wakeup events while the controller is suspended.) The USB core does not automatically stop polling when the root hub is suspended; you have to stop it yourself. There's a race here; if you really want to make sure no polls occur while the hardware is stopped then you have to call del_timer_sync(&hcd->rh_timer). An interesting question is whether to re-enable polling when the root hub resumes. I suppose an easy approach is always to enable polling and request an immediate poll. Then your hub_status_data will turn off polling if it isn't needed. 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
