This allow to prevent deadlock on entering KDB if one of evdev locks is
already taken by userspace process.
Also this change discards all but LED console events produced by KDB as
unrelated to userspace.
Tested by: dumbbell (as part of D15070)
Objected by: bde (as 'KDB lock an already locked mutex' problem solution)
MFC after: 1 month
Now evdev part of keyboard drivers does not take any locks if corresponding
input/eventN device node is not opened by userland consumers.
Do not assert console lock inside evdev to handle the cases when keyboard
driver is called from some special single-threaded context like shutdown
thread.
Automaticaly release (send ABS_MT_TRACKING_ID = -1) MT-slots
that has not been listed in current MT protocol type B report.
Slot is counted as listed if corresponding ABS_MT_SLOT event
has been sent regardless of other MT events.
Events are sent on SYN_REPORT event.
Submitted by: Vladimir Kondratiev <wulf@cicgroup.ru>
Add new API call: evdev_register_mtx which takes lock argument that
should be used instead of internal one for evdev locking. Useful for
cases if evdev_push_event() is always called with driver's lock taken
and reduces amount of lock aquisitions. This allows to avoid LOR
between ev_open/ev_close invocations and evdev_push_event() Such LOR
can happen when ev_open/ev_close methods acquire driver lock and
evdev_push_event() is called with this lock taken.
Submitted by: Vladimir Kondratiev <wulf@cicgroup.ru>
evdev is a generic input event interface compatible with Linux
evdev API at ioctl level. It allows using unmodified (apart from
header name) input evdev drivers in Xorg, Wayland, Qt.
This commit has only generic kernel API. evdev support for individual
hardware drivers like ukbd, ums, atkbd, etc. will be committed later.
Project was started by Jakub Klama as part of GSoC 2014. Jakub's
evdev implementation was later used as a base, updated and finished
by Vladimir Kondratiev.
Submitted by: Vladimir Kondratiev <wulf@cicgroup.ru>
Reviewed by: adrian, hans
Differential Revision: https://reviews.freebsd.org/D6998
