>> After reading section 4.8 of EHCI spec again. I have another question: >> Does HC will increase the asynclistaddr to next QH which follow the QH >> of which H bit set to 1?? > > You mean, does it do this when it stops following the schedule? No, it > doesn't. If doesn't go processing next qh, the asynclistaddr will point to the same QH of which H bit =1, doesn't it?? >> I read the code in qh_link_async() adding >> the new queue after the ehci->async. So I think it is not possible to >> restart the asynchronous when the sleep timer expires without >> advancing to next QH. If doesn't, HC will read the same QH of H = 1 >> and sleep again. > > It won't sleep again right away, because when the schedule restarts > the Reclamation bit is set to 1. See 4.8.3. But if hc won't go ahead to next qh of which H!=1, it will still go to sleep again. Because hc still process the original qh(H=1) ??. Gavin Guo -- 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