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| author | Ben Gamari <ben@smart-cactus.org> | 2016-10-04 11:40:44 -0700 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2016-10-04 11:46:51 -0700 |
| commit | a831776323e7c532ef9c88d0d62512ae15d78415 (patch) | |
| tree | 08b81fcc217d0a8cacb721feda78d85c738aa810 /drivers/input | |
| parent | 4777ac220c430173e297237b896932ed5fd8aaf3 (diff) | |
| download | linux-a831776323e7c532ef9c88d0d62512ae15d78415.tar.gz linux-a831776323e7c532ef9c88d0d62512ae15d78415.tar.bz2 linux-a831776323e7c532ef9c88d0d62512ae15d78415.zip | |
Input: ALPS - handle 0-pressure 1F events
While a button is held SS5 hardware will give us single-finger packets
with x, y, and pressure equal to zero. This causes annoying jumps in
pointer position if a touch is released while the button is held. Handle
this by claiming zero contacts to ensure that no position events are
provided to the user.
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Tested-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Ben Gamari <ben@smart-cactus.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'drivers/input')
| -rw-r--r-- | drivers/input/mouse/alps.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c index 8e15783d2932..a76e5c6fce54 100644 --- a/drivers/input/mouse/alps.c +++ b/drivers/input/mouse/alps.c @@ -1198,7 +1198,13 @@ static int alps_decode_ss4_v2(struct alps_fields *f, f->mt[0].x = SS4_1F_X_V2(p); f->mt[0].y = SS4_1F_Y_V2(p); f->pressure = ((SS4_1F_Z_V2(p)) * 2) & 0x7f; - f->fingers = 1; + /* + * When a button is held the device will give us events + * with x, y, and pressure of 0. This causes annoying jumps + * if a touch is released while the button is held. + * Handle this by claiming zero contacts. + */ + f->fingers = f->pressure > 0 ? 1 : 0; f->first_mp = 0; f->is_mp = 0; break; |