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authorHans de Goede <hdegoede@redhat.com>2020-10-27 06:53:57 +0300
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2020-10-27 06:56:28 +0300
commitb1884583fcd17d6a1b1bba94bbb5826e6b5c6e17 (patch)
treee8fda4e295dd4678743ff7f765bd74a13fc023d7 /drivers/input/serio
parent33b6c39e747c552fa770eecebd1776f1f4a222b1 (diff)
downloadlinux-b1884583fcd17d6a1b1bba94bbb5826e6b5c6e17.tar.xz
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>
Diffstat (limited to 'drivers/input/serio')
-rw-r--r--drivers/input/serio/i8042.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
index d3eda48032e3..944cbb519c6d 100644
--- a/drivers/input/serio/i8042.c
+++ b/drivers/input/serio/i8042.c
@@ -122,6 +122,7 @@ module_param_named(unmask_kbd_data, i8042_unmask_kbd_data, bool, 0600);
MODULE_PARM_DESC(unmask_kbd_data, "Unconditional enable (may reveal sensitive data) of normally sanitize-filtered kbd data traffic debug log [pre-condition: i8042.debug=1 enabled]");
#endif
+static bool i8042_present;
static bool i8042_bypass_aux_irq_test;
static char i8042_kbd_firmware_id[128];
static char i8042_aux_firmware_id[128];
@@ -343,6 +344,9 @@ int i8042_command(unsigned char *param, int command)
unsigned long flags;
int retval;
+ if (!i8042_present)
+ return -1;
+
spin_lock_irqsave(&i8042_lock, flags);
retval = __i8042_command(param, command);
spin_unlock_irqrestore(&i8042_lock, flags);
@@ -1612,12 +1616,15 @@ static int __init i8042_init(void)
err = i8042_platform_init();
if (err)
- return err;
+ return (err == -ENODEV) ? 0 : err;
err = i8042_controller_check();
if (err)
goto err_platform_exit;
+ /* Set this before creating the dev to allow i8042_command to work right away */
+ i8042_present = true;
+
pdev = platform_create_bundle(&i8042_driver, i8042_probe, NULL, 0, NULL, 0);
if (IS_ERR(pdev)) {
err = PTR_ERR(pdev);
@@ -1636,6 +1643,9 @@ static int __init i8042_init(void)
static void __exit i8042_exit(void)
{
+ if (!i8042_present)
+ return;
+
platform_device_unregister(i8042_platform_device);
platform_driver_unregister(&i8042_driver);
i8042_platform_exit();