On Tue, 7 Sep 2004, Kyle Harris wrote: > I'm fairly new to USB, please forgive my ignorance. The Cypress HC requires > that each TD specifiy the port, address, and ep. So it seems that the URB > data would be sent to a single port. I don't understand how this would work > if data is sent to the port that does not contain the addressed device. Each > port is independent on this controller. Maybe that means I actually have 4 > root hubs?
I don't think so. If you tried it, it wouldn't work since each pair of ports shares a single SIE. This means that you can't use the full bandwidth of both ports simultaneously. That would mess up bandwidth reservation, if nothing else. A cleaner solution is to treat the pair of ports as a single root hub, and keep track of which port each device lies below. The problem with this approach is that the existing data structures don't give you any place to store that information! Nor does the code for adding new devices provide the hook you would need. The easiest thing for now is to ignore the second port in each pair. Unless you can specify in a TD that it should use both ports? Alan Stern ------------------------------------------------------- This SF.Net email is sponsored by BEA Weblogic Workshop FREE Java Enterprise J2EE developer tools! Get your free copy of BEA WebLogic Workshop 8.1 today. http://ads.osdn.com/?ad_id=5047&alloc_id=10808&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
