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| author | Dave Carey <carvsdriver@gmail.com> | 2026-05-14 22:32:58 +0300 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.com> | 2026-06-10 19:28:19 +0300 |
| commit | ef257b8be9776915ca468bae6c91e31757e69734 (patch) | |
| tree | e143d846d4db2c87c7f555271253f20fa803f06d /include | |
| parent | f1bd44b9b62c6fbdaacdd5d115ebe3fe543fcfa1 (diff) | |
| download | linux-ef257b8be9776915ca468bae6c91e31757e69734.tar.xz | |
HID: multitouch: Honor ContactCount for Yoga Book 9 to suppress ghost contacts
The INGENIC 17EF:6161 firmware on the Lenovo Yoga Book 9 14IAH10
does not clear stale contact slots when fingers are lifted. Each
HID report contains up to 10 finger slots, but only the first
ContactCount slots represent valid contacts; the remaining slots
retain TipSwitch=1 with positions from previous touches.
Raw HID capture confirms this: across a 60-second capture with
repeated multi-finger gestures, 90% of frames had more TipSwitch=1
slots than the reported ContactCount. The ContactCount field itself
is always accurate.
Add MT_QUIRK_CONTACT_CNT_ACCURATE to the MT_CLS_YOGABOOK9I class so
the driver stops processing slots once ContactCount valid contacts
have been consumed, discarding the stale ghost entries per HID
specification section 17. MT_QUIRK_NOT_SEEN_MEANS_UP (already in
the class) ensures that any slot skipped by this guard is released
via INPUT_MT_DROP_UNUSED at frame sync.
Signed-off-by: Dave Carey <carvsdriver@gmail.com>
Tested-by: Dave Carey <carvsdriver@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
Diffstat (limited to 'include')
0 files changed, 0 insertions, 0 deletions