It is possible that the client list lock is taken by other process for too
long due to e.g. IO timeouts. Allow user to terminate open() in this case.
Reviewed by: markj (as part of D27865)
At the beginning of evdev there was a LOR between hardware driver's and
evdev client list locks as they were taken in different order at
driver's interrupt and evdev open()/close() handlers.
The LOR was fixed with introduction of evdev_register_mtx() function
which allowed to use a hardware driver's lock as evdev client list lock.
While this works good with PS/2 and USB, this does not work with I2C.
Unlike PS/2 and USB, I2C open()/close() handlers do unbound sleeps
while waiting for I2C bus to release and while performing IO.
This change uses epoch(9) for traversing evdev client list in interrupt
handler to avoid the LOR thus making possible to convert evdev client
list lock to sleepable sx.
While here add brief locking protocol description.
Reviewed by: markj
Differential revision: https://reviews.freebsd.org/D27865
Incompatibility between i386 and amd64 evdev ABIs was caused by presence of
'struct timeval' in evdev protocol. Replace it with 'struct timeval32' for
32 bit binaries.
Big-endian platforms may require additional work due to bitstr_t (array of
unsigned longs) usage in ioctl interface.
MFC after: 2 weeks
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 softc should be retrieved from struct edvev * pointer
with evdev_get_softc() helper.
wmt(4) is a sample of driver that support both KPI.
Reviewed by: hselasky, gonzo
Differential Revision: https://reviews.freebsd.org/D16614
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
