touchpad: only keep low-pressure fingers alive for 2+-slot touchpads

Regression introduced by 3979b9e16a5ed141506d95f80ddfd7b94651dcfa, bug 105258.
With that commit, we only ended real touches when we had less than nslots fake
fingers down. i.e. tripletap on a 2 slot touchpad would not end the
first/second touch even if the pressure goes below the threshold. e.g. Lenovo
x270 needs this, see https://bugs.freedesktop.org/attachment.cgi?id=137672, it
dips below the pressure threshold for the first slot and ends the second slot
in the same frame as the third finger is detected. Fun times.

Anyway, this breaks semi-mt touchpads, another fine category of devices,
because some of those can detect hovering fingers at low pressure, see bug
105535. Because semi-mt devices are generally garbage, we treat them as
single-touch devices instead. So whenever two fingers are down, we treat both
as above the pressure threshold, even when they're physicall hovering.

Fix this by making the x270 fix conditional on at least 2 slots.

https://bugs.freedesktop.org/show_bug.cgi?id=105535

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
(cherry picked from commit 3f5ff113a8c9469b084941b3b3157d7da95600d1)

diff --git a/src/evdev-mt-touchpad.c b/src/evdev-mt-touchpad.c
index a3d69a198011c7d38da7da4408c4f22f08d3f5f6..c803b1dc554eb665fa81968622073c3ddde30e94 100644 (file)
--- a/src/evdev-mt-touchpad.c
+++ b/src/evdev-mt-touchpad.c
@@ -1147,8 +1147,12 @@ tp_unhover_pressure(struct tp_dispatch *tp, uint64_t time)
                                        tp_begin_touch(tp, t, time);
                                }
                        /* don't unhover for pressure if we have too many
-                        * fake fingers down, see comment below */
-                       } else if (nfake_touches <= tp->num_slots) {
+                        * fake fingers down, see comment below. Except
+                        * for single-finger touches where the real touch
+                        * decides for the rest.
+                        */
+                       } else if (nfake_touches <= tp->num_slots ||
+                                  tp->num_slots == 1) {
                                if (t->pressure < tp->pressure.low) {
                                        evdev_log_debug(tp->device,
                                                        "pressure: end touch\n");

diff --git a/test/test-touchpad-tap.c b/test/test-touchpad-tap.c
index af8981c797978431d2e3cb3d622242a012405b0d..1639d796880f4bc9e660b8ea461810fc56461e55 100644 (file)
--- a/test/test-touchpad-tap.c
+++ b/test/test-touchpad-tap.c
@@ -1619,7 +1619,11 @@ START_TEST(touchpad_3fg_tap_pressure_btntool)
        litest_touch_move_to(dev, 1, 70, 50, 50, 70, 10, 0);
        litest_drain_events(li);
 
-       /* drop below the pressure threshold in the same frame as starting a */
+       /* drop below the pressure threshold in the same frame as starting a
+        * third touch, see
+        *   E: 8713.954784 0001 014e 0001 # EV_KEY / BTN_TOOL_TRIPLETAP   1
+        * in https://bugs.freedesktop.org/attachment.cgi?id=137672
+        */
        litest_event(dev, EV_ABS, ABS_MT_PRESSURE, 3);
        litest_event(dev, EV_ABS, ABS_PRESSURE, 3);
        litest_event(dev, EV_KEY, BTN_TOOL_DOUBLETAP, 0);

diff --git a/test/test-touchpad.c b/test/test-touchpad.c
index 98f9b6205f29b233ee35441c72becf52afa4a933..427fc13ccb46ce124580010d7e8258c415d270f2 100644 (file)
--- a/test/test-touchpad.c
+++ b/test/test-touchpad.c
@@ -5489,6 +5489,45 @@ START_TEST(touchpad_pressure_btntool)
 }
 END_TEST
 
+START_TEST(touchpad_pressure_semi_mt_2fg_goes_light)
+{
+       struct litest_device *dev = litest_current_device();
+       struct libinput *li = dev->libinput;
+       struct axis_replacement axes[] = {
+               { ABS_PRESSURE, 2 },
+               { -1, 0 }
+       };
+
+       litest_enable_2fg_scroll(dev);
+       litest_drain_events(li);
+
+       litest_touch_down(dev, 0, 40, 50);
+       litest_touch_down(dev, 1, 60, 50);
+       litest_touch_move_two_touches(dev, 40, 50, 60, 50, 0, -20, 10, 0);
+
+       /* This should trigger a scroll end event */
+       litest_push_event_frame(dev);
+       litest_touch_move_extended(dev, 0, 40, 31, axes);
+       litest_touch_move_extended(dev, 1, 60, 31, axes);
+       litest_pop_event_frame(dev);
+       libinput_dispatch(li);
+
+       litest_assert_scroll(li, LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL, 0);
+
+       litest_push_event_frame(dev);
+       litest_touch_move_extended(dev, 0, 40, 35, axes);
+       litest_touch_move_extended(dev, 1, 60, 35, axes);
+       litest_pop_event_frame(dev);
+
+       litest_push_event_frame(dev);
+       litest_touch_move_extended(dev, 0, 40, 40, axes);
+       litest_touch_move_extended(dev, 1, 60, 40, axes);
+       litest_pop_event_frame(dev);
+       libinput_dispatch(li);
+       litest_assert_empty_queue(li);
+}
+END_TEST
+
 static inline bool
 touchpad_has_touch_size(struct litest_device *dev)
 {
@@ -5873,6 +5912,7 @@ litest_setup_tests_touchpad(void)
        litest_add("touchpad:pressure", touchpad_pressure_tap_2fg, LITEST_TOUCHPAD, LITEST_ANY);
        litest_add("touchpad:pressure", touchpad_pressure_tap_2fg_1fg_light, LITEST_TOUCHPAD, LITEST_SINGLE_TOUCH);
        litest_add("touchpad:pressure", touchpad_pressure_btntool, LITEST_TOUCHPAD, LITEST_SINGLE_TOUCH);
+       litest_add("touchpad:pressure", touchpad_pressure_semi_mt_2fg_goes_light, LITEST_SEMI_MT, LITEST_ANY);
 
        litest_add("touchpad:touch-size", touchpad_touch_size, LITEST_APPLE_CLICKPAD, LITEST_ANY);
        litest_add("touchpad:touch-size", touchpad_touch_size_2fg, LITEST_APPLE_CLICKPAD, LITEST_ANY);