On Wed, Feb 8, 2012 at 11:43 AM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: >> The >> host timeout for SETUP packets > > You mean the timeout for control transfers, not SETUP packets. > Yes, that is what I mean. >> should be on the order of seconds - > > "should be" ... but might not be. Hi Alan, I spent a little time looking at the usb sources. Do you know if the hcd times out control transfers? Where does it do it? Technically it is not required, the host could just continue to be NAKed forever. > >> which should be enough for the gadget to get its endpoints ready. > > It's true that in normal operation we will not have to worry about > this race. Nevertheless, drivers should be written to handle even edge > cases and unlikely races correctly. > > Alan Stern > I agree we should cover worst case. However determining what that timing is can be difficult. I have seen some devices that were very slow at enumeration, so probably all we can say is all devices are fast enough to enumerate under Windows. So whoever is most impatient, Linux or Windows will set the longest time we can hold off the host before completing a control transaction. Coming up with that time is tricky. Regards, Steve -- 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
