Re: PROBLEM: Regression likely in hid_uclogic driver breaks Huion Inspiroy H640 drawing tablet

["José Expósito" <jose.exposito89@gmail.com>]

Hi Benjamin,

On Thu, Aug 11, 2022 at 05:23:52PM +0200, Benjamin Tissoires wrote:
> On Thu, Aug 4, 2022 at 8:24 PM José Expósito <jose.exposito89@gmail.com> wrote:
> >
> > Hi again,
> >
> > On 2022-07-26 18:48, José Expósito wrote:
> > > The first bad commit is 87562fcd1342 ("HID: input: remove the need for
> > > HID_QUIRK_INVERT"):
> > > https://lore.kernel.org/all/20220203143226.4023622-11-benjamin.tissoires@redhat.com/
> > > (CCing the folks whose email is in the patch tags)
> > >
> > > I reverted the patch on hid/for-next and, after fixing a tiny conflict,
> > > I can confirm that the tablet works again as expected.
> > >
> > > I'd need to investigate a bit more over the weekend, but I think that
> > > all HUION tablets with the latest firmware (internally, v2) are
> > > affected.
> >
> > Indeed, it looks like v2 devices are affected. Similar reports:
> >
> >  - https://github.com/DIGImend/digimend-kernel-drivers/issues/626
> >  - https://bugzilla.kernel.org/show_bug.cgi?id=216106
> >
> > Kindly sending this thread back to your inbox to see if we could fix
> > this regression.
> 
> [sorry, I was out on vacation the past 2 weeks and this week was the
> usual "urgent" thing I have to day for yesterday]

No problem, I hope you enjoyed your holidays :D 

> Ideally, I'd like to not revert that commit. It solves a bunch of
> issues on many devices, so that's maybe not the way forward.
>
> FWIW, it was quite painful to tweak and that was a solution that
> matches the hid-multitouch devices I could find.
> 
> I tried to process your email when you described the succession of
> events without much success.
> 
> Would you mind dumping a hid-record when exposing the bug?

Sure, I added as an attachment in the existing report in bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=216106#c2

I hope it helps you to debug the issue. Let me know if you need more
recordings, help testing patches or any other information.

In future changes to tablet code, feel free to cc me. I have a bunch of
non Wacom devices and I'll help you testing your changes.

Best wishes,
Jose

> Cheers,
> Benjamin
> 
> 
> >
> > Best wishes,
> > Jose
> >
> > > Those tablets do not set the inrange bit (UCLOGIC_PARAMS_PEN_INRANGE_NONE).
> > > The driver sets it and uses a timer to remove it.
> > > See drivers/hid/hid-uclogic-core.c, function uclogic_raw_event_pen().
> > > [...]
> >
>