Hi Laurent,

Laurent Pinchart wrote:
>> i've spent some time on the Microsoft Xbox Live Vision cam (it's pretty
>> cheap, USB 2.0, nearly uvc 1.0 compliant, has a pretty good image
>> quality, manual focus, allegedly a 1280x960 sensor (i haven't checked,
>> it might just upscale, but i don't think so), and supports MJPG and YUYV).
> *nearly* UVC compliant ? *sigh*... Can't they test their hardware with 
> Linux ? :-)
*g*

Well, given that the thing is designed for a gaming console, I consider
it as an advancement already that it a.) doesn't have a proprietary
connector, and b.) at least tries to follow SOME standard, and c.)
doesn't try to put all the magic into the host.

> SET_INTERFACE shouldn't be required. Upon being plugged in, the webcam should 
> select the default alternate setting.
here is a lsusb -v:

http://tmb.elitedvb.net/lsusb_045e0294

What's with that "Xbox Security Method 3" interface? So that's not the
default interface? (We can/should totally ignore that interface, it's
only an optional authentication between the host and the device. I just
want to be sure that this is not the default interface.)

>> b.) The cam requires about ~3sec time after the initial SET_INTERFACE.
> Now this is bad news. What happens if you query controls during those ~3sec ? 
> Those the webcam timeout but stay functional, or does it crash ?
It stays functional. It just responds with NAKs, and then, after it has
initialized itself, it answers (unless, of course, the transaction has
been cancelled).

> I'll test the SET_INTERFACE part and commit it soon. Regarding the timeouts, 
> what happens if you modify the streaming timeout only ?
I can currently not test it, because the cam is operating at a remote
place (and I don't want to risk a crash), but I can this test tomorrow.
My guess it that it will work, because the streaming command is done first.

I still vote for a dummy transaction after the SET_INTERFACE with a long
timeout, to make sure the cam has initialized itself. After that the
short timeout should suffice. Just incrementing the timeout is a bad
thing, i'd say.

Felix
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