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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 e39c0df1be ("pwm: Introduce the pwm_args concept").

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Fixes: e39c0df1be ("pwm: Introduce the pwm_args concept")
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
This commit is contained in:
Boris Brezillon 2016-05-17 14:27:25 +02:00 committed by Thierry Reding
parent e39c0df1be
commit fbd45a1298
1 changed files with 17 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
drivers/pwm/core.c
View File

@ -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;