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From:   =?UTF-8?q?Jos=C3=A9=20Exp=C3=B3sito?= <jose.exposito89@gmail.com>
To:     spbnick@gmail.com
Cc:     jikos@kernel.org, benjamin.tissoires@redhat.com,
        linux-input@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [RFC] UCLogic: Filtering unsupported HUION tablets
Date:   Mon, 18 Jul 2022 19:29:53 +0200
Message-Id: <20220718172953.6817-1-jose.exposito89@gmail.com>
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Hi!

No code yet, just a kind request for comments and hopefully some wisdom
and experience from Nikolai dealing with HUION devices.

HUION keeps reusing the same vendor and product IDs for their devices.
This makes it really difficult to differentiate between devices and
handle them in the kernel and also in user space.

Reusing IDs could introduce a problem:

If HUION, or other vendor following the same practices, releases a new
tablet with a duplicated product ID, the UCLogic driver would handle it.
The device might work with the existing code or it might fail because of
a new feature or a whole different firmware.

As far as I know, at the moment there is not a mechanism in place to
avoid this situation.
I think that it'd be better to ignore those devices in UCLogic and let
the HID generic driver handle them because using HID generic would
provide a basic user experience while using UCLogic might fail to probe
the tablet.

DIGImend's web already provides a nice list of supported devices:
http://digimend.github.io/tablets/

So, I wonder:

 - Do you think it makes sense to ignore untested devices?
 - If the answer is yes, do we have a better option than checking the
   device name against an allow-list? It'd be great to hear other
   people's ideas.

Best wishes,
José Expósito