Hi Jiada,
input_mt_report_slot_state() ignores the tool when the slot is closed.
which has caused a bit of confusion.
This patch introduces input_mt_report_slot_inactive() to report slot
inactive state.
replaces all input_mt_report_slot_state() with
input_mt_report_slot_inactive() in case of close of slot.
This patch looks very odd, I am afraid.
When a driver needs to use input_mt functions, it first calls
input_mt_init_slots() during setup. The MT state then remains in effect
until the driver is destroyed. Thus, there is no valid case when
input_mt_report_slot_state() would fail to execute the line
input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1)
when active == false.
What input_mt_report_slot_state() does do, however, is to ignore the
event when no MT state has been set, which does happen for some drivers
handling both normal and MT devices. Changing such a driver in the way
you suggest would introduce new events in existing, working cases, and
possibly break userspace. We should try very hard to avoid it.
Thanks,
Henrik