Messages in this thread Patch in this message | | | From | Benjamin Tissoires <> | Subject | [PATCH 2/2] Input - synaptics: pin 3 touches when the firmware reports 3 fingers | Date | Wed, 22 Apr 2015 11:45:09 -0400 |
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Synaptics PS/2 touchpad can send only 2 touches in a report. They can detect 4 or 5 and this information is valuable.
In commit 63c4fda3c0bb ("Input: synaptics - allocate 3 slots to keep stability in image sensors"), we allocate 3 slots, but we still continue to report the 2 available fingers. That means that the client sees 2 used slots while there is a total of 3 fingers advertised by BTN_TOOL_TRIPLETAP.
For old kernels this is not a problem because max_slots was 2 and libinput/ xorg-synaptics knew how to deal with that. Now that max_slot is 3, the clients ignore BTN_TOOL_TRIPLETAP and count the actual used slots (so 2). It then gets confused when receiving the BTN_TOOL_TRIPLETAP and DOUBLETAP information, and goes wild.
We can pin the 3 slots until we get a total number of fingers below 2.
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1212230
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> --- drivers/input/mouse/synaptics.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c index 630af73..c69b308 100644 --- a/drivers/input/mouse/synaptics.c +++ b/drivers/input/mouse/synaptics.c @@ -935,6 +935,14 @@ static void synaptics_report_mt_data(struct psmouse *psmouse, input_report_abs(dev, ABS_MT_PRESSURE, hw[i]->z); } + /* keep (slot count <= num_fingers) by pinning all slots */ + if (num_fingers >= 3) { + for (i = 0; i < 3; i++) { + input_mt_slot(dev, i); + input_mt_report_slot_state(dev, MT_TOOL_FINGER, true); + } + } + input_mt_drop_unused(dev); /* Don't use active slot count to generate BTN_TOOL events. */ -- 2.1.0
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