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 <[email protected]> --- 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(-) --- base-commit: 54ba6d9b1393a0061600c0e49c8ebef65d60a8b2 change-id: 20250926-fix-sticky-fingers-8ae88436ae82 Best regards, -- Benjamin Tissoires <[email protected]>
