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Date:   Sat, 23 Jul 2022 13:40:53 +0200 (CEST)
From:   Jiri Kosina <jikos@kernel.org>
To:     Stefan Hansson <newbie13xd@gmail.com>
cc:     benjamin.tissoires@redhat.com, linux-input@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        =?ISO-8859-15?Q?Jos=E9_Exp=F3sito?= <jose.exposito89@gmail.com>
Subject: Re: PROBLEM: Regression likely in hid_uclogic driver breaks Huion
 Inspiroy H640 drawing tablet
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On Fri, 22 Jul 2022, Stefan Hansson wrote:

> Hi!
> 
> Somewhere between Linux 5.17.6 and 5.18.11 the Huion tablet I have stopped
> working properly. In GNOME Control Center it is identified as Huion New 1060
> Plus, however that's a different tablet than the one I have. Mine is a Huion
> Inspiroy H640, and it uses the hid_uclogic driver.
> 
> With Linux 5.17.6, the tablet works as expected with all the buttons being
> detected and the stylus being usable. With 5.18.11, the buttons work fine but
> the stylus does not work correctly. The first time I approach the tablet with
> the stylus it works properly, i.e., the cursor on my screen moves around and
> follows the stylus around the tablet as expected. It continues working like
> this until I remove the stylus from the tablet. After I remove it from the
> tablet, the cursor never gets controlled by the stylus again. I can see that
> the tablet detects the stylus (it has a small indicator light), but the cursor
> doesn't move when I approach the tablet again. To clarify, with Linux 5.17.6,
> the cursor moves around just fine when I remove and then put it back to the
> tablet, just as you would expected.
> 
> It may also be worth noting that it worked fine when I previously used it
> around six months ago, although I'm not sure what version of Linux I was using
> at that time (whatever Fedora shipped back then). I also tried reproducing it
> with yesterday's linux-next and Linux 5.19.0-RC7, and the behaviour was the
> same as 5.18.11. I am currently trying to bisect this, but it's not going very
> fast as I currently only have access to a dual core laptop from 2014, so
> building Linux takes a good while.

Thanks for the report. CCing José who has been doing a lot of work in this 
area recently, maybe he has an immediate idea.

If not, perhaps bisecting the hid-uclogic.c commits between the two 
kernels would be the quickest option.

-- 
Jiri Kosina
SUSE Labs