Send an extra ABS_MT_SLOT event to sync the client up with the current slot

If multiple slots have changed during the sync handling, the client must be
re-set to the current slot before continuing with normal events.

Signed-off-by: Benjamin Tissoires <btissoir@redhat.com>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>

diff --git a/libevdev/libevdev.c b/libevdev/libevdev.c
index 7ba4629..958580f 100644 (file)
--- a/libevdev/libevdev.c
+++ b/libevdev/libevdev.c
@@ -551,9 +551,12 @@ out:
 static int
 sync_mt_state(struct libevdev *dev, int create_events)
 {
+       struct input_event *ev;
+       struct input_absinfo abs_info;
        int rc;
        int axis, slot;
        int ioctl_success = 0;
+       int last_reported_slot = 0;
        struct mt_state {
                int code;
                int val[MAX_SLOTS];
@@ -599,14 +602,18 @@ sync_mt_state(struct libevdev *dev, int create_events)
                }
        }
 
-       for (slot = 0; create_events && slot < min(dev->num_slots, MAX_SLOTS); slot++) {
-               struct input_event *ev;
+       if (!create_events) {
+               rc = 0;
+               goto out;
+       }
 
+       for (slot = 0; slot < min(dev->num_slots, MAX_SLOTS); slot++) {
                if (!bit_is_set(slot_update, AXISBIT(slot, ABS_MT_SLOT)))
                        continue;
 
                ev = queue_push(dev);
                init_event(dev, ev, EV_ABS, ABS_MT_SLOT, slot);
+               last_reported_slot = slot;
 
                for (axis = ABS_MT_MIN; axis <= ABS_MT_MAX; axis++) {
                        if (axis == ABS_MT_SLOT ||
@@ -620,6 +627,20 @@ sync_mt_state(struct libevdev *dev, int create_events)
                }
        }
 
+       /* add one last slot event to make sure the client is on the same
+          slot as the kernel */
+
+       rc = ioctl(dev->fd, EVIOCGABS(ABS_MT_SLOT), &abs_info);
+       if (rc < 0)
+               goto out;
+
+       dev->current_slot = abs_info.value;
+
+       if (dev->current_slot != last_reported_slot) {
+               ev = queue_push(dev);
+               init_event(dev, ev, EV_ABS, ABS_MT_SLOT, dev->current_slot);
+       }
+
 #undef AXISBIT
 
        rc = 0;

diff --git a/test/test-libevdev-events.c b/test/test-libevdev-events.c
index 5d38c62..eca8a94 100644 (file)
--- a/test/test-libevdev-events.c
+++ b/test/test-libevdev-events.c
@@ -585,6 +585,93 @@ START_TEST(test_syn_delta_mt)
 }
 END_TEST
 
+START_TEST(test_syn_delta_mt_reset_slot)
+{
+       struct uinput_device* uidev;
+       struct libevdev *dev;
+       int rc;
+       struct input_event ev,
+                          last_slot_event = { .type = 0};
+       struct input_absinfo abs[6];
+
+       memset(abs, 0, sizeof(abs));
+       abs[0].value = ABS_X;
+       abs[0].maximum = 1000;
+       abs[1].value = ABS_MT_POSITION_X;
+       abs[1].maximum = 1000;
+
+       abs[2].value = ABS_Y;
+       abs[2].maximum = 1000;
+       abs[3].value = ABS_MT_POSITION_Y;
+       abs[3].maximum = 1000;
+
+
+       abs[4].value = ABS_MT_SLOT;
+       abs[4].maximum = 1;
+       abs[5].value = ABS_MT_TRACKING_ID;
+       abs[5].minimum = -1;
+       abs[5].maximum = 2;
+
+       rc = test_create_abs_device(&uidev, &dev,
+                                   6, abs,
+                                   EV_SYN, SYN_REPORT,
+                                   -1);
+       ck_assert_msg(rc == 0, "Failed to create device: %s", strerror(-rc));
+
+       uinput_device_event(uidev, EV_ABS, ABS_MT_SLOT, 1);
+       uinput_device_event(uidev, EV_ABS, ABS_MT_POSITION_X, 100);
+       uinput_device_event(uidev, EV_ABS, ABS_MT_POSITION_Y, 500);
+       uinput_device_event(uidev, EV_ABS, ABS_MT_TRACKING_ID, 1);
+       uinput_device_event(uidev, EV_ABS, ABS_MT_SLOT, 0);
+       uinput_device_event(uidev, EV_ABS, ABS_MT_POSITION_X, 1);
+       uinput_device_event(uidev, EV_ABS, ABS_MT_POSITION_Y, 5);
+       uinput_device_event(uidev, EV_ABS, ABS_MT_TRACKING_ID, 2);
+       uinput_device_event(uidev, EV_SYN, SYN_REPORT, 0);
+
+       rc = libevdev_next_event(dev, LIBEVDEV_READ_FLAG_FORCE_SYNC, &ev);
+       ck_assert_int_eq(rc, LIBEVDEV_READ_STATUS_SYNC);
+
+       do {
+               rc = libevdev_next_event(dev, LIBEVDEV_READ_FLAG_SYNC, &ev);
+               if (libevdev_event_is_code(&ev, EV_ABS, ABS_MT_SLOT))
+                       last_slot_event = ev;
+       } while (rc != -EAGAIN);
+
+       ck_assert(libevdev_event_is_code(&last_slot_event, EV_ABS, ABS_MT_SLOT));
+       ck_assert_int_eq(last_slot_event.value, 0);
+       ck_assert_int_eq(libevdev_get_current_slot(dev), 0);
+
+       last_slot_event.type = 0;
+
+       /* same thing again, this time swap the numbers */
+       uinput_device_event(uidev, EV_ABS, ABS_MT_SLOT, 0);
+       uinput_device_event(uidev, EV_ABS, ABS_MT_POSITION_X, 100);
+       uinput_device_event(uidev, EV_ABS, ABS_MT_POSITION_Y, 500);
+       uinput_device_event(uidev, EV_ABS, ABS_MT_TRACKING_ID, 1);
+       uinput_device_event(uidev, EV_ABS, ABS_MT_SLOT, 1);
+       uinput_device_event(uidev, EV_ABS, ABS_MT_POSITION_X, 1);
+       uinput_device_event(uidev, EV_ABS, ABS_MT_POSITION_Y, 5);
+       uinput_device_event(uidev, EV_ABS, ABS_MT_TRACKING_ID, 2);
+       uinput_device_event(uidev, EV_SYN, SYN_REPORT, 0);
+
+       rc = libevdev_next_event(dev, LIBEVDEV_READ_FLAG_FORCE_SYNC, &ev);
+       ck_assert_int_eq(rc, LIBEVDEV_READ_STATUS_SYNC);
+
+       do {
+               rc = libevdev_next_event(dev, LIBEVDEV_READ_FLAG_SYNC, &ev);
+               if (libevdev_event_is_code(&ev, EV_ABS, ABS_MT_SLOT))
+                       last_slot_event = ev;
+       } while (rc != -EAGAIN);
+
+       ck_assert(libevdev_event_is_code(&last_slot_event, EV_ABS, ABS_MT_SLOT));
+       ck_assert_int_eq(last_slot_event.value, 1);
+       ck_assert_int_eq(libevdev_get_current_slot(dev), 1);
+
+       uinput_device_free(uidev);
+       libevdev_free(dev);
+}
+END_TEST
+
 START_TEST(test_syn_delta_mt_too_many)
 {
        struct uinput_device* uidev;
@@ -656,6 +743,11 @@ START_TEST(test_syn_delta_mt_too_many)
                ck_assert_int_lt(slot, MAX_SLOTS);
 
                rc = libevdev_next_event(dev, LIBEVDEV_READ_FLAG_SYNC, &ev);
+
+               /* last MT_SLOT event is on its own */
+               if (libevdev_event_is_code(&ev, EV_SYN, SYN_REPORT))
+                       break;
+
                ck_assert_int_eq(rc, LIBEVDEV_READ_STATUS_SYNC);
                ck_assert_int_eq(ev.type, EV_ABS);
                ck_assert_int_eq(ev.code, ABS_MT_POSITION_X);
@@ -1590,6 +1682,7 @@ libevdev_events(void)
        tcase_add_test(tc, test_syn_delta_abs);
        tcase_add_test(tc, test_syn_delta_mt);
        tcase_add_test(tc, test_syn_delta_mt_too_many);
+       tcase_add_test(tc, test_syn_delta_mt_reset_slot);
        tcase_add_test(tc, test_syn_delta_led);
        tcase_add_test(tc, test_syn_delta_sw);
        tcase_add_test(tc, test_syn_delta_fake_mt);