|Summary:||Potential incorrect ClickFinger count on three finger click|
|Product:||xorg||Reporter:||Allan McRae <allan>|
|Component:||Input/synaptics||Assignee:||Peter Hutterer <peter.hutterer>|
|Status:||RESOLVED FIXED||QA Contact:|
|i915 platform:||i915 features:|
Description Allan McRae 2012-04-04 20:49:50 UTC
Commit 420e0abe (Guess the number of clickpad ClickFingers based on finger distance) introduced limiting the number of fingers involved in a multifinger click by putting a maximum distance between pairs of fingers. However, with a three finger click, with all fingers close together, all three possible pairs of fingers can be separated by less the tested distance. Thus a click involving four fingers is reported. This leads to a situation where you are required to three finger click with your fingers not too close together, but also not too far apart...
Comment 1 Allan McRae 2012-04-04 20:55:30 UTC
This could be fixed by adding something like: if(nfingers > hw->num_mt_mask - 1) nfingers = hw->num_mt_mask - 1; above the return statement in clickpad_guess_clickfingers. This would have the advantage of allowing the percentage touchpad width that pairs of fingers are required to be within to be increased, as 30% is quite small for some touchpads.
Comment 2 Peter Hutterer 2012-04-09 22:28:50 UTC
Created attachment 59706 [details] [review] 0001-Don-t-count-fingers-twice-when-guessing-distance-483.patch I don't have hardware to test this, please do so. You'll also need http://patchwork.freedesktop.org/patch/9827/ for the new define.
Comment 3 Allan McRae 2012-04-10 17:55:48 UTC
That patch corrects the overcounting of fingers issue. Now when I three finger click, three or less fingers are detected (depending on separation).
Comment 4 Peter Hutterer 2012-04-11 18:13:41 UTC
New patch, fixes bug in previous algorithm: http://patchwork.freedesktop.org/patch/9906/