On Wed, 27 Nov 2024 17:10:34 +0100,
"Lorenz (xha)" <me@xha.li> wrote:
> 
> hi Kirill,
> 
> On Tue, Nov 26, 2024 at 11:51:56PM +0100, Kirill A. Korinsky wrote:
> > tech@,
> > 
> > I had figured out why the Jabra PanaCast 20 wouldn't start streaming. It
> > needs uvideo_vs_negotiation between usbd_set_interface and usbd_open_pipe.
> > Once I'd added it, it just started working.
> > 
> > Putting it before usbd_set_interface or after usbd_open_pipe doesn't help.
> > 
> > I am not sure if I should enable it only for this webcam via quirks or keep
> > it for everything. I had tested on Azurewave, USB camera which is embedded
> > in my laptop, this diff doesn't affect it and it continues to work as if
> > nothing had changed.
> > 
> > I guess it might fix some webcams that don't work today.
> > 
> > 
> > Feedback? Tests? Ok?
> >

+mglocker@ to CC

> > +	/* do device negotiation witht commit after switch interface */
> 
> there's a typo here :)
>

Here a version with a bit better wording.

Index: sys/dev/usb/uvideo.c
===================================================================
RCS file: /home/cvs/src/sys/dev/usb/uvideo.c,v
diff -u -p -r1.223 uvideo.c
--- sys/dev/usb/uvideo.c	27 Nov 2024 11:37:23 -0000	1.223
+++ sys/dev/usb/uvideo.c	27 Nov 2024 16:50:14 -0000
@@ -1899,6 +1899,12 @@ uvideo_vs_open(struct uvideo_softc *sc)
 		return (USBD_INVAL);
 	}
 
+	/* do device negotiation with commit after set alternate interface */
+	error = uvideo_vs_negotiation(sc, 1);
+	if (error != USBD_NORMAL_COMPLETION)
+		printf("%s: could not negotiate after setting alternate interface!\n",
+		    DEVNAME(sc));
+
 	DPRINTF(1, "%s: open pipe for bEndpointAddress=0x%02x\n",
 	    DEVNAME(sc), sc->sc_vs_cur->endpoint);
 	error = usbd_open_pipe(

-- 
wbr, Kirill