From: Benjamin Tissoires Date: Thu, 16 Apr 2015 13:01:46 -0400 Subject: [PATCH] Input - synaptics: pin 3 touches when the firmware reports 3 fingers 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 63c4fda (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 --- 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 630af73e98c4..c69b308beb3f 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. */