On Wed, 8 Oct 2025, Benjamin Tissoires wrote:
> According to Peter, we've had for a very long time an issue on some
> mutltiouch touchpads where the fingers were stuck in a scrolling mode,
> or 3 fingers gesture mode. I was unable to debug it because it was
> rather hard to reproduce.
>
> Recently, some people raised the issue again on libinput, and this time
> added a recording of the actual bug.
>
> It turns out that the sticky finger quirk that was introduced back in
> 2017 was only checking the last report, and that those missing releases
> also happen when moving from 3 to 1 finger (only 1 is released instead
> of 2).
>
> This solution seems to me to be the most sensible, because we could also
> add the NSMU quirk to win8 multitouch touchpads, but this would involve
> a lot more computations at each report for rather annoying corner cases.
>
> Link: https://gitlab.freedesktop.org/libinput/libinput/-/issues/1194
> Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
> ---
> Benjamin Tissoires (2):
> HID: multitouch: fix sticky fingers
> selftests/hid: add tests for missing release on the Dell Synaptics
>
> drivers/hid/hid-multitouch.c | 27 ++++++-----
> .../testing/selftests/hid/tests/test_multitouch.py | 55 ++++++++++++++++++++++
> 2 files changed, 69 insertions(+), 13 deletions(-)
Now queued in for-6.18/upstream-fixes. Thanks,
--
Jiri Kosina
SUSE Labs