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

[Ran Wang]

Hi Alan,

On Sunday, September 29, 2019 10:35, wrote:
> 
> Hi Alan,
> 
> On Saturday, September 28, 2019 01:08, Alan Stern wrote:
<snip>
> >
> > In fact, the system should respond the same way to any unrecognized
> > device that doesn't support HNP, right?  There's nothing special about
> > these VID/PID values.
> 
> Yes, but I saw there are already some implementation in upstream kernel for this
> purpose, just PID different: drivers/usb/core/otg_whitelist.h function
> is_targeted()
> 
> > > > And why those specific vid/pid values?  What do they refer to?
> > >
> > > For step 5, we got the VID / PID number from USB IF certified
> > > lab(Allion.inc at Taiwang). Looks like this is a reserved ID pair
> > > and will not be allocated to any vendor for their products. So it's
> > > hence used for
> > this case test (like saying: you should be able to pop a not-support
> > message for this reserved VID&PID).
> >
> > Don't we do this already?
> 
> Yes, but in function is_stargeted(), I found it's a little be different:
> Current upstream:                     VID = 0x1a0a, PID = 0x0200
> Info from USB-IF certified lab: VID = 0x1a0a, PID = 0x0201
> 

Sorry that I mis-understood the logic of is_stargeted() and it's caller.

So the proper way to resolve my problem is:
1. Select CONFIG_USB_OTG in .config
2. Add property 'tpl-support' to device tree
3. Customize whitelist_table[] according to my Target-Peripheral-List
requirement.

Am I right? :)

Regards,
Ran