[systemd-devel] WebUSB

[Greg KH]

On Mon, Jan 09, 2017 at 01:32:40PM -0800, Reilly Grant wrote:
> On 2017-01-09 9:55 am, Greg KH wrote:
> > On Mon, Jan 09, 2017 at 06:13:04PM +0100, Bjørn Mork wrote:
> > > Greg KH <greg at kroah.com> writes:
> > > > On Mon, Jan 09, 2017 at 09:40:59AM +0000, Kenneth Rohde Christiansen wrote:
> > > >> Web USB can only grab devices which has special Web USB headers. It can not
> > > >> grab any USB device.
> > > >>
> > > >> https://wicg.github.io/webusb/#webusb-descriptors
> > > >
> > > > Ah, fun :(
> > > >
> > > > So, we can add a quirk into the kernel cdc-acm driver to never bind to a
> > > > device that has the wusb platform capability descriptor,
> > > 
> > > I fail to see why a quirk should be necessary. New device classes are
> > > expected to use new class/subclass codes distintly different from
> > > anything handled by existing class drivers.
> > 
> > One would hope, but it seems like they want to piggy-back on the cdc-acm
> > spec.  But I could be totally wrong here, does anyone have the actual
> > descriptor dump of a device anywhere?
> 
> We don't want to piggy-back on the CDC-ACM spec. A WebUSB device should
> always have its interfaces marked vendor-specific. Below is an example of a
> device which implements both a CDC-ACM interface and a WebUSB interface.

Ick, why would you want both interfaces on a device?  Are you going to
allow firmware to talk to both endpoints at the same time?  Why?

Why not just make it a "one interface" type of device?

thanks,

greg k-h