[PATCH 4.14 015/183] Input: pwm-vibra - prevent unbalanced regulator

[Greg Kroah-Hartman]

4.14-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-rac...@live.ca>
Signed-off-by: Paweł Chmiel <pawel.mikolaj.chm...@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torok...@gmail.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 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