[PATCH 4.9 29/32] Input: elan_i2c - fix regulator enable count imbalance after suspend/resume

Greg Kroah-Hartman
2022-03-07T09:21:27Z

From: Hans de Goede <hdegoede@redhat.com>

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>
---
drivers/input/mouse/elan_i2c_core.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

--- a/drivers/input/mouse/elan_i2c_core.c
+++ b/drivers/input/mouse/elan_i2c_core.c
@@ -1184,17 +1184,17 @@ static int __maybe_unused elan_resume(st
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);