Re: [PATCHv2] usb: gadget: get rid of USB_GADGET_DUALSPEED andUSB_GADGET_SUPERSPEED

[Alan Stern]

On Fri, 19 Aug 2011, Michal Nazarewicz wrote:

> > I don't quite understand that sentence.  However, it is definitely true
> > that all UDC drivers _must_ avoid connecting at speeds that are faster
> > than the usb_gadget_driver's .speed field.
> 
> Yang has brought up an issue that musb_gadget_start() checks if  
> driver->speed
> equals USB_SPEED_HIGH.  This means that if a gadget driver supports super  
> speed
> it'll set driver->speed to USB_SPEED_SUPER and musb_gadget_start() will  
> complain.
> 
> My understanding is that this is a bug in musb driver as it should allow  
> the
> gadget driver to start but never set super speed.

That's right.  It should also allow driver->speed to be USB_SPEED_FULL, 
in which case it should never connect at high speed (see gmidi.c).

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/