USB device driver question: timeout() and usbd_do_request()

[Rita Lin]

> Igh - that sounds like a very bad device design then.
> There would have been lots a ways to do in a clean way without
> additional pipes - such as transfering 0 sized packets to trigger a
> status inquiry or by adding status bytes in each packet.
> For what purpose do you need to poll the status in case for this device?
I would not say it's a very bad device design. However, I do agree with you
that there are numerous way to implement it. Most devices generate
interrupts
when there is a modem status change. This particular device does
not support interrupts.

> Yes that's possible as long a you have separate pipes for each channel.
> But if you have separate pipes for each channel then the device could
> use separate USB interfaces as well so you can attach seprate instances
> of your driver as well without doing special handling.
> --
> B.Walter                   BWCT                http://www.bwct.de
> bernd at bwct.de                                  info at bwct.de
>
That is correct provided that xxx_softc is handled correctly, otherwise, you
will end up handling wrong ucom_softc each time when driver specific
routines are called. I didn't do any special handling in my driver methods.

As I mentioned earlier, I only did a trick in declaring the xxx_softc.
ucom_attach() attaches one instance of my driver. I made this comment
because I saw some earlier posts about ucom needed modification to support
multiple ports.

Rita