On Fri, 20 Nov 2009, Ivan Braginski wrote: > On Fri, Nov 20, 2009 Greg KH wrote: > > [...] > > > I'm trying to use an evaluation board as USB gadget, but when I > > > connect it to a host, the host says "unknown device" and VID and PID > > > are both 0000. So the device descriptor is empty or not sent properly. > > > > Not necessarily, I've seen vid and pid set to 0000 in some devices. > > How so? For example, in the drivers g-serial and g-zero, the VID is set to 0x0525. Why is it set to 0000 later? What can I do to avoid this? > > > [...] > > > Can you point me out, which function does listen to the host, or which > > > function actually sends the device descriptor? It does not have to be > > > in pxa27x-udc, I would also appreciate, if you can show this in any > > > other driver, because I only want to see, what such code looks like. > > > > The USB core handles all of this for you on the host side. On the > > gadget side, it is in the "type" of device that you have specified to be > > built for your device. What type did you set? > > Sorry, you mean the type of the device driver? Then, it is g-serial as CDC-ACM, but also others like g-zero as normal type. (The drivers are compiled as modules and modprobed with no parameter.) In g_zero, the device descriptor is sent by composite_setup() in composite.c. In g_file_storage, the device descriptor is sent by standard_set_req() in file_storage.c. Alan Stern -- 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
