Commit fbd45a12 authored by Boris Brezillon's avatar Boris Brezillon Committed by Thierry Reding
Browse files

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 e39c0df1 ("pwm: Introduce the pwm_args concept").

Signed-off-by: default avatarBoris Brezillon <boris.brezillon@free-electrons.com>
Fixes: e39c0df1 ("pwm: Introduce the pwm_args concept")
Signed-off-by: default avatarThierry Reding <thierry.reding@gmail.com>
parent e39c0df1

drivers/pwm/core.c

+17 −10
Original line number Diff line number Diff line
@@ -128,13 +128,6 @@ 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;

}
@@ -627,6 +620,13 @@ 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);
@@ -754,13 +754,20 @@ 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;

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