Re: ni_usb with multiple devices

On Thu, Dec 6, 2018 at 8:33 PM Frank Mori Hess <[email protected]> wrote:
>
> On Thu, Dec 6, 2018 at 2:46 AM dave penkler <[email protected]> wrote:
> >
> > BTW there is support for multiple cards in the USB hotplug scripts. See cut and paste from INSTALL below:
> >
> > Using multiple-boards of the same type with hotplug requires
> > udev support: In the hotplug scripts you can use either the
> > serial number $SERIAL or the device path $DEVPATH to decide
>
> It doesn't seem robust though, for example during boot when two
> devices may appear nearly simultaneously.  Really, the SERIAL/DEVPATH
> should be passed to gpib_config and the driver would use them to
> verify it has found the correct board.

Ok, I looked into this a bit more, the drivers can use
kobject_get_path() to get the DEVPATH on the kernel side.  I'm
thinking of just replacing the "device tree path" stuff I added with a
more generic support for specifying hardware by DEVPATH.  Probably no
one has started using the "device tree path" stuff yet (it only works
with the fmh_gpib driver) so changing it won't break anyone's code.

-- 
Frank