UPSTREAM: pwm: Fix pwm_apply_args() call sites

pwm_apply_args() is supposed to initialize a PWM device according to the
arguments provided by the DT or the PWM lookup, but this function was
called inside pwm_device_request(), which in turn was called before the
core had a chance to initialize the pwm->args fields.

Fix that by calling pwm_apply_args directly in pwm_get() and of_pwm_get()
after initializing pwm->args field.

This commit also fixes an invalid pointer dereference introduced by
commit e39c0df1be5a ("pwm: Introduce the pwm_args concept").

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Fixes: e39c0df1be5a ("pwm: Introduce the pwm_args concept")
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
(cherry picked from commit fbd45a12988e75a48d392feb8b0e5feb5d612513)

Change-Id: I9746f4ada57a6cc8155bafe662a63c82338c223a
Signed-off-by: David Wu <david.wu@rock-chips.com>

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 8fbd7c5d34b6ba177dd1c6fcffe8585044472df0..7bb31429886eb7baa1bdd14a652cf014c4443c33 100644 (file)
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -129,13 +129,6 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label)
        set_bit(PWMF_REQUESTED, &pwm->flags);
        pwm->label = label;
 
-       /*
-        * FIXME: This should be removed once all PWM users properly make use
-        * of struct pwm_args to initialize the PWM device. As long as this is
-        * here, the PWM state and hardware state can get out of sync.
-        */
-       pwm_apply_args(pwm);
-
        return 0;
 }
 
@@ -630,6 +623,13 @@ struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id)
 
        pwm->label = con_id;
 
+       /*
+        * FIXME: This should be removed once all PWM users properly make use
+        * of struct pwm_args to initialize the PWM device. As long as this is
+        * here, the PWM state and hardware state can get out of sync.
+        */
+       pwm_apply_args(pwm);
+
 put:
        of_node_put(args.np);
 
@@ -757,13 +757,20 @@ struct pwm_device *pwm_get(struct device *dev, const char *con_id)
        if (!chip)
                goto out;
 
-       pwm->args.period = chosen->period;
-       pwm->args.polarity = chosen->polarity;
-
        pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id);
        if (IS_ERR(pwm))
                goto out;
 
+       pwm->args.period = chosen->period;
+       pwm->args.polarity = chosen->polarity;
+
+       /*
+        * FIXME: This should be removed once all PWM users properly make use
+        * of struct pwm_args to initialize the PWM device. As long as this is
+        * here, the PWM state and hardware state can get out of sync.
+        */
+       pwm_apply_args(pwm);
+
 out:
        mutex_unlock(&pwm_lookup_lock);
        return pwm;