Attaching ugen to all usb devices

[Joao Barros]

On 12/25/06, M. Warner Losh <imp at bsdimp.com> wrote:
> In message: <200612251456.42770.amistry at am-productions.biz>
>             Anish Mistry <amistry at am-productions.biz> writes:
> :       Many usb devices can be attached as different devices along with
> : being functional with some libusb app that requires ugen.
> : eg.  HP PSC Printers will attach as ulpt, if ulpt isn't loaded umass
> : can attach to access the card slot, if neither of these are loaded
> : ugen will attach which is required to run the hplip vendor software
> : so that the printer, scanner, and fax machine can be accessed.
>
> You should review how the device presents itself to the system.  If
> both umass and ulpt attach to it, it should be possible to make them
> both attach at the same time.
>
> As for ugen, one could easily hack uhub to allow this kind of access.
> ugen really shouldn't be attaching to any device at all, but instead
> the usb bus (aka uhub) should allow ugen-like acess to each of the
> devices.
>
> :       It would be very helpful to allow ulpt, umass, and ugen to all attach
> : to the device.  This would allow full functionality.  Simultaneous
> : access isn't necessary, but might be nice in the future.
>
> That would be a nightmare.  Trust me.  I've looked into it in the past
> it was scary.
>
> :       The closest thing I can think of that allows similar behavior is
> : vgapci that allow acpi_video and a drm driver to both access the
> : video card.
>
> Well, it doesn't really.  newbus has a very strong notion of each node
> in the tree has one and only one (or zero) devices attached.
>
> Warner

My Huawei E220 USB HSDPA modem presents 3 devices to the system. If I
connect the modem I get the virtual storage device, but if I load
ubsec into the kernel I will only get the ubsec device. I haven't yet
tried to access the 3rd device, it's another serial port.
I think the goal here it to be able to access all the devices.

-- 
Joao Barros