Where to find USB VID and PID?

[Greg Freemyer]

On Tue, Feb 4, 2014 at 2:54 PM, Eric Fowler <eric.fowler at gmail.com> wrote:
>  I have an Emcraft SmartFusion2 board with a USB interface, running
> ucLinux. When I plug the board to a Windows machine, said Win machine
> sees an 'unknown device', which usually (always) means VID_0000 and
> PID_0000. This is separate and independent of the USB and JTAG
> interfaces that are used for programming, network access, and
> debugging, which are all working as expected.
>
> How do I:
> - Find the device on the linux side that maps to that endpoint, if it
> exists (I have already found the device object for the root hub)
> - Interrogate for the VID & PID that a given USB device presents to
> the connecting host
> - Manipulate the VID & PID on a USB device on ucLinux
>
> --
> cc:NSA

I assume you want to do it in the kernel and I don't know the
mechanism for that.

lsusb can do the interrogate from userspace, so you can use strace to
see what kernel API is uses.  Then trace that into the kernel.

Greg