Werner Almesberger wrote:
But all these solutions still need protocol stack changes on both ends,
right ? That makes them fairly unattractive unless it's something all
relevant hosts implement ...
I have not yet had the chance to use compound gadgets. AIUI, a specific
host driver is needed for composite gadgets, not for compound gadgets.
This paragraph (4.8.2.2) from the USB2.0 spec defines compound devices:
"A function is a USB device that is able to transmit or receive data or
control information over the bus. A function is typically implemented as
a separate peripheral device with a cable that plugs into a port on a
hub. However, a physical package may implement multiple functions and an
embedded hub with a single USB cable. This is known as a compound
device. A compound device appears to the host as a hub with one or more
non-removable USB devices."
Gilles
