Input: elan_i2c - fix regulator enable count imbalance after suspend/resume

BugLink: https://bugs.launchpad.net/bugs/1964361
commit 04b7762e37c95d9b965d16bb0e18dbd1fa2e2861 upstream.

Before these changes elan_suspend() would only disable the regulator
when device_may_wakeup() returns false; whereas elan_resume() would
unconditionally enable it, leading to an enable count imbalance when
device_may_wakeup() returns true.

This triggers the "WARN_ON(regulator->enable_count)" in regulator_put()
when the elan_i2c driver gets unbound, this happens e.g. with the
hot-plugable dock with Elan I2C touchpad for the Asus TF103C 2-in-1.

Fix this by making the regulator_enable() call also be conditional
on device_may_wakeup() returning false.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220131135436.29638-2-hdegoede@redhat.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/drivers/input/mouse/elan_i2c_core.c b/drivers/input/mouse/elan_i2c_core.c
index 185191b86fadb52d83458d6c857cda3a4d9143eb..e1758d5ffe421831f64a198daa5db33e920c3033 100644 (file)
--- a/drivers/input/mouse/elan_i2c_core.c
+++ b/drivers/input/mouse/elan_i2c_core.c
@@ -1388,17 +1388,17 @@ static int __maybe_unused elan_resume(struct device *dev)
        struct elan_tp_data *data = i2c_get_clientdata(client);
        int error;
 
-       if (device_may_wakeup(dev) && data->irq_wake) {
+       if (!device_may_wakeup(dev)) {
+               error = regulator_enable(data->vcc);
+               if (error) {
+                       dev_err(dev, "error %d enabling regulator\n", error);
+                       goto err;
+               }
+       } else if (data->irq_wake) {
                disable_irq_wake(client->irq);
                data->irq_wake = false;
        }
 
-       error = regulator_enable(data->vcc);
-       if (error) {
-               dev_err(dev, "error %d enabling regulator\n", error);
-               goto err;
-       }
-
        error = elan_set_power(data, true);
        if (error) {
                dev_err(dev, "power up when resuming failed: %d\n", error);