Re: [RFC] UCLogic: Filtering unsupported HUION tablets

[Nikolai Kondrashov]

On 7/20/22 20:36, José Expósito wrote:
> Hi Nikolai,
>
> Thanks a lot for the quick response.
>
> On Tue, Jul 19, 2022 at 12:57:09PM +0300, Nikolai Kondrashov wrote:
> > Hi José,
> >
> > First of all, thanks a lot for all the work you're doing with the tablets!
> >
> > Yes, this situation is unfortunate, but there's really not much we could do.
> > The tablet database at http://digimend.github.io/tablets/ hasn't been
> > updated in ages, and it has never been exhaustive to start with.
> >
> > There are tons of tablet modifications, including of the same (marketed)
> > model, and those can differ not only in the reported name, but probably even
> > the VID:PID, as could've happened when Huion switched from v1 to v2
> > protocol.
> >
> > So, I think a "whitelist" would be a maintenance nightmare.
> >
> > Moreover, I think it's better to disable the tablet completely in case we
> > failed initialization (e.g. got an invalid response to configuration, or
> > failed to find some interfaces and such), after producing a comprehensive
> > error message. Configuring a tablet partially, and then handing it over to
> > the generic driver could mess things up more.
> >
> > It's less confusing for the user, and stops them from trying to fix the
> > problem up the stack with various settings, often getting into a worse
> > situation. It's also much easier for the maintainer, since they don't need
> > to investigate all the higher layers.
> >
> > A "blacklist" would work better here, if you can find the tablets to include.
> >
> > Nick
>
> That makes sense, thanks for the pointers.
>
> It is unfortunate that we don't have the required information about the
> supported tablets. Excluding the unsupported tablets (when fixing them
> is not possible for reasons) seems like a reasonable approach.
>
> I don't know about any broken device handled by the driver, so there is
> no need to add new code yet :)
> I'll try to keep an eye on DIGImend's issue tracker now that the code
> present in the upstream kernel is being released by many distros.

If you have the time, backporting your changes to digimend-kernel-drivers 
would get you feedback much faster :)

I can do a release once we get the code in.

Nick