Effects were allocated, but not freed anywhere.

Signed-off-by: Jari Vanhala <ext-jari.vanhala@nokia.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Function name is input_ff_destroy() and not input_ff_free()

Signed-off-by: Roger Quadros <roger.quadros@nokia.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Now that input core acquires dev->event_lock spinlock and disables
interrupts when propagating input events, using spin_lock_bh() in
ff-memless driver is not allowed. Actually, the timer_lock itself
is not needed anymore, we should simply use dev->event_lock
as well.

Also do a small cleanup in force-feedback core.

Reported-by: kerneloops.org
Reported-by: http://www.kerneloops.org/searchweek.php?search=ml_ff_set_gain
Reported-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Commit 656acd2bbc4ce7f224de499ee255698701396c48 ("Input: fix locking in
force-feedback core") causes the following regression on m68k:

| linux/drivers/input/ff-core.c: In function 'input_ff_upload':
| linux/drivers/input/ff-core.c:172: error: dereferencing pointer to incomplete type
| linux/drivers/input/ff-core.c: In function 'erase_effect':
| linux/drivers/input/ff-core.c:197: error: dereferencing pointer to incomplete type
| linux/drivers/input/ff-core.c:204: error: dereferencing pointer to incomplete type
| make[4]: *** [drivers/input/ff-core.o] Error 1

As the incomplete type is `struct task_struct', including <linux/sched.h> fixes
it.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The newly added event_lock spinlock in the input core disallows sleeping
and therefore using mutexes in event handlers. Convert force-feedback
core to rely on event_lock instead of mutex to protect slots allocated
for fore-feedback effects. The original mutex is still used to serialize
uploading and erasing of effects.

Reported-by: Anssi Hannula <anssi.hannula@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Make sure that requested effect id is not out of range for the
device and that effect is present before requesting device to
play it.

Reported-by: Jan Kratochvil <honza@jikos.cz>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Add input subsystem to kernel-api docbook.
Enhance some function and parameter comments.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

Implement a new force feedback interface, in which all non-driver-specific
operations are separated to a common module. This includes handling effect
type validations, locking, etc.

The effects are now file descriptor specific instead of the previous strange
half-process half-fd specific behaviour. The effect memory of devices is not
emptied if the root user opens and closes the device while another user is
using effects. This is a minor change and most likely no force feedback
aware programs are affected by this negatively.

Otherwise the userspace interface is left unaltered.

Signed-off-by: Anssi Hannula <anssi.hannula@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>