[PATCH 4.19 032/280] Input: pwm-vibra - prevent unbalanced regulator

From: Greg Kroah-Hartman
Date: Fri Mar 22 2019 - 08:48:59 EST


4.19-stable review patch. If anyone has any objections, please let me know.

------------------

[ Upstream commit 3ca232df9921f083c3b37ba5fbc76f4d9046268b ]

pwm_vibrator_stop disables the regulator, but it can be called from
multiple places, even when the regulator is already disabled. Fix this
by using regulator_is_enabled check when starting and stopping device.

Signed-off-by: Jonathan Bakker <xc-racer2@xxxxxxx>
Signed-off-by: PaweÅ Chmiel <pawel.mikolaj.chmiel@xxxxxxxxx>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/input/misc/pwm-vibra.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/input/misc/pwm-vibra.c b/drivers/input/misc/pwm-vibra.c
index 55da191ae550..9df87431d7d4 100644
--- a/drivers/input/misc/pwm-vibra.c
+++ b/drivers/input/misc/pwm-vibra.c
@@ -34,6 +34,7 @@ struct pwm_vibrator {
struct work_struct play_work;
u16 level;
u32 direction_duty_cycle;
+ bool vcc_on;
};

static int pwm_vibrator_start(struct pwm_vibrator *vibrator)
@@ -42,10 +43,13 @@ static int pwm_vibrator_start(struct pwm_vibrator *vibrator)
struct pwm_state state;
int err;

- err = regulator_enable(vibrator->vcc);
- if (err) {
- dev_err(pdev, "failed to enable regulator: %d", err);
- return err;
+ if (!vibrator->vcc_on) {
+ err = regulator_enable(vibrator->vcc);
+ if (err) {
+ dev_err(pdev, "failed to enable regulator: %d", err);
+ return err;
+ }
+ vibrator->vcc_on = true;
}

pwm_get_state(vibrator->pwm, &state);
@@ -76,7 +80,10 @@ static int pwm_vibrator_start(struct pwm_vibrator *vibrator)

static void pwm_vibrator_stop(struct pwm_vibrator *vibrator)
{
- regulator_disable(vibrator->vcc);
+ if (vibrator->vcc_on) {
+ regulator_disable(vibrator->vcc);
+ vibrator->vcc_on = false;
+ }

if (vibrator->pwm_dir)
pwm_disable(vibrator->pwm_dir);
--
2.19.1