linux/drivers/input
Hans de Goede b1884583fc Input: i8042 - allow insmod to succeed on devices without an i8042 controller
The i8042 module exports several symbols which may be used by other
modules.

Before this commit it would refuse to load (when built as a module itself)
on systems without an i8042 controller.

This is a problem specifically for the asus-nb-wmi module. Many Asus
laptops support the Asus WMI interface. Some of them have an i8042
controller and need to use i8042_install_filter() to filter some kbd
events. Other models do not have an i8042 controller (e.g. they use an
USB attached kbd).

Before this commit the asus-nb-wmi driver could not be loaded on Asus
models without an i8042 controller, when the i8042 code was built as
a module (as Arch Linux does) because the module_init function of the
i8042 module would fail with -ENODEV and thus the i8042_install_filter
symbol could not be loaded.

This commit fixes this by exiting from module_init with a return code
of 0 if no controller is found.  It also adds a i8042_present bool to
make the module_exit function a no-op in this case and also adds a
check for i8042_present to the exported i8042_command function.

The latter i8042_present check should not really be necessary because
when builtin that function can already be used on systems without
an i8042 controller, but better safe then sorry.

Reported-and-tested-by: Marius Iacob <themariusus@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20201008112628.3979-2-hdegoede@redhat.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2020-10-26 20:56:28 -07:00
..
gameport treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
joystick Input: joystick - add ADC attached joystick driver. 2020-09-28 16:26:11 -07:00
keyboard Input: twl4030_keypad - fix handling of platform_get_irq() error 2020-09-16 10:42:15 -07:00
misc Input: adxl34x - clean up a data type in adxl34x_probe() 2020-10-26 20:56:27 -07:00
mouse Merge branch 'next' into for-linus 2020-10-18 18:42:32 -07:00
rmi4 Input: synaptics-rmi4 - support bootloader v8 in f34v7 2020-10-04 19:51:45 -07:00
serio Input: i8042 - allow insmod to succeed on devices without an i8042 controller 2020-10-26 20:56:28 -07:00
tablet Input: Use fallthrough pseudo-keyword 2020-07-07 11:25:54 -07:00
touchscreen Input: add zinitix touchscreen driver 2020-10-04 16:08:09 -07:00
apm-power.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
evbug.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
evdev.c Input: evdev - per-client waitgroups 2020-10-06 18:34:15 -07:00
ff-core.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
ff-memless.c Input: ff-memless - kill timer in destroy() 2019-11-15 11:45:03 -08:00
input-compat.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
input-compat.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
input-leds.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
input-mt.c Input: MT - avoid comma separated statements 2020-08-25 10:26:05 -07:00
input-polldev.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
input-poller.c Input: add input_get_poll_interval() 2019-10-04 12:31:46 -07:00
input-poller.h Input: add support for polling to input devices 2019-08-20 12:04:07 -07:00
input.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2020-03-26 20:49:44 -07:00
joydev.c Linux 5.2 2019-07-15 09:42:32 -07:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile Input: add support for polling to input devices 2019-08-20 12:04:07 -07:00
matrix-keymap.c Input: matrix-keymap - switch to use device_property_count_u32() 2019-08-12 00:03:13 -07:00
mousedev.c *: convert stream-like files -> stream_open, even if they use noop_llseek 2019-07-14 16:09:19 +03:00
sparse-keymap.c Input: Use fallthrough pseudo-keyword 2020-07-07 11:25:54 -07:00