Re: Questions about usb hub
David Brownell <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
On Sunday 01 July 2007, jidong xiao wrote: > Take root hub for example, how does the hub itself know whether its > upstream facing port is connected at high-speed or > full-speed? There *IS* no upstream facing port. The upstream link hooks to a non-USB bus. > Futhermore, if a host send a GET_DESCRIPTOR request to a > hub, how does it know which set of descriptor should be reported? For non-root hubs, the answer is obvious: the right one according to the spec (high speed vs low speed) and hardware capabilities (e.g. TT-per port, per-hub, or not). For root hubs, any answer whatsoever is out-of-spec. All that's important is that Linux not confuse itself by the answer it gives. ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel