RE: [PATCH] usb: hub add filter for device with specific VID&PID

[Ran Wang]

Hi Alan,

On Monday, September 23, 2019 23:01, Alan Stern wrote:
> 
> On Mon, 23 Sep 2019, Ran Wang wrote:
> 
> > USB 2.0 Embedded Host PET Automated Test (CH6) 6.7.23 A-UUT
> > "Unsupported Device" Message require to stop enumerating device with
> > VID=0x1a0a PID=0x0201 and pop message to declare this device is not
> supported.
> >
> > Signed-off-by: Ran Wang <ran.wang_1@xxxxxxx>
> > ---
> >  drivers/usb/core/hub.c | 12 ++++++++++++
> >  1 file changed, 12 insertions(+)
> >
> > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index
> > bbcfa63..3cda0da 100644
> > --- a/drivers/usb/core/hub.c
> > +++ b/drivers/usb/core/hub.c
> > @@ -4982,6 +4982,18 @@ static void hub_port_connect(struct usb_hub *hub,
> int port1, u16 portstatus,
> >  		if (status < 0)
> >  			goto loop;
> >
> > +		 /* USB 2.0 Embedded Host PET Automated Test (CH6)
> > +		 * 6.7.23 A-UUT "Unsupported Device" Message
> > +		 * require to filter out below device when enumeration
> > +		 */
> > +		if ((udev->descriptor.idVendor == 0x1a0a)
> > +		 && (udev->descriptor.idProduct == 0x0201)) {
> > +			dev_err(&udev->dev, "This device is not supported:
> idVendor=0x%x idProduct=0x%x\n",
> > +				udev->descriptor.idVendor,
> > +				udev->descriptor.idProduct);
> 
> There's no need to write out the Vendor and Product IDs.  They already appear
> in the "New device" message.

OK

> > +			goto done;
> > +		}
> > +
> >  		if (udev->quirks & USB_QUIRK_DELAY_INIT)
> >  			msleep(2000);
> 
> Shouldn't this be implemented as a device quirk?

Yes, I was also looking for the way in quirk but not quite sure currently.
So we can stop initializing a device (with specific VID&PID) in quirk, right?

Actually in drivers/usb/core/hub.c function usb_enumerate_device(), it will
call is_targeted(udev) which has below implementation:

54         /* OTG PET device is always targeted (see OTG 2.0 ECN 6.4.2) */          
55         if ((le16_to_cpu(dev->descriptor.idVendor) == 0x1a0a &&                   
56              le16_to_cpu(dev->descriptor.idProduct) == 0x0200))                  
57                 return 1;    

The ID is very close to what I need to response. So, do I need to add code here?

Thanks.
Ran