Re: [PATCH] hid-mt: Fix Cirque 121f touch release

[Jason Andryuk]

On Mon, Oct 19, 2020 at 9:05 AM Jason Andryuk <jandryuk@xxxxxxxxx> wrote:
>
> We're seeing the touchpad not send all the touch release events.  This
> can result in the cursor getting stuck generating scroll events instead
> of cursor movement for single finger motion.  With the cursor not
> moving, users think the trackpad is broken.  With libinput-record, you
> can see that it doesn't always get to a neutral state when there are no
> fingers on the touchpad.
>
> MT_QUIRK_STICKY_FINGERS was insufficient alone.  The timer often didn't
> fire to release all the contacts.  MT_QUIRK_NOT_SEEN_MEANS_UP seems to
> help with tracking the touches, and allows the timer to fire properly
> when needed.
>
> You can reproduce by touching the trackpad with 4 fingers spread out,
> then pulling them all together and removing from the track pad.

<snip>

> ---
> This is developed and tested against 5.4 and forward ported to latest
> upstream.

I installed Fedora 32 with kernel 5.6.6 to test out some other stuff,
and it is not reproducing with the steps above.  Is there some other
change that may have fixed the release tracking?  I was definitely
seeing it with 5.4.72.

Regards,
Jason