Commit ae52f797 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'pwm/for-6.3-rc6' of... 

Merge tag 'pwm/for-6.3-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm fixes from Thierry Reding:
 "These are some fixes to make sure the PWM state structure is always
  initialized to a known state.

  Prior to this it could happen in some situations that random data from
  the stack would leak into the data structure and cause subtle bugs"

* tag 'pwm/for-6.3-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
  pwm: Zero-initialize the pwm_state passed to driver's .get_state()
  pwm: meson: Explicitly set .polarity in .get_state()
  pwm: sprd: Explicitly set .polarity in .get_state()
  pwm: iqs620a: Explicitly set .polarity in .get_state()
  pwm: cros-ec: Explicitly set .polarity in .get_state()
  pwm: hibvt: Explicitly set .polarity in .get_state()
parents ac6c0433 1271a7b9

drivers/pwm/core.c

+10 −2
Original line number Diff line number Diff line
@@ -115,7 +115,14 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label) 
	}



	if (pwm->chip->ops->get_state) {

		struct pwm_state state;

		/*

		 * Zero-initialize state because most drivers are unaware of

		 * .usage_power. The other members of state are supposed to be

		 * set by lowlevel drivers. We still initialize the whole

		 * structure for simplicity even though this might paper over

		 * faulty implementations of .get_state().

		 */

		struct pwm_state state = { 0, };



		err = pwm->chip->ops->get_state(pwm->chip, pwm, &state);

		trace_pwm_get(pwm, &state, err);
@@ -448,7 +455,7 @@ static void pwm_apply_state_debug(struct pwm_device *pwm, 
{

	struct pwm_state *last = &pwm->last;

	struct pwm_chip *chip = pwm->chip;

	struct pwm_state s1, s2;

	struct pwm_state s1 = { 0 }, s2 = { 0 };

	int err;



	if (!IS_ENABLED(CONFIG_PWM_DEBUG))
@@ -530,6 +537,7 @@ static void pwm_apply_state_debug(struct pwm_device *pwm, 
		return;

	}



	*last = (struct pwm_state){ 0 };

	err = chip->ops->get_state(chip, pwm, last);

	trace_pwm_get(pwm, last, err);

	if (err)

drivers/pwm/pwm-cros-ec.c

+1 −0
Original line number Diff line number Diff line
@@ -198,6 +198,7 @@ static int cros_ec_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, 


	state->enabled = (ret > 0);

	state->period = EC_PWM_MAX_DUTY;

	state->polarity = PWM_POLARITY_NORMAL;



	/*

	 * Note that "disabled" and "duty cycle == 0" are treated the same. If

drivers/pwm/pwm-hibvt.c

+1 −0
Original line number Diff line number Diff line
@@ -146,6 +146,7 @@ static int hibvt_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, 


	value = readl(base + PWM_CTRL_ADDR(pwm->hwpwm));

	state->enabled = (PWM_ENABLE_MASK & value);

	state->polarity = (PWM_POLARITY_MASK & value) ? PWM_POLARITY_INVERSED : PWM_POLARITY_NORMAL;



	return 0;

}

drivers/pwm/pwm-iqs620a.c

+1 −0
Original line number Diff line number Diff line
@@ -126,6 +126,7 @@ static int iqs620_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, 
	mutex_unlock(&iqs620_pwm->lock);



	state->period = IQS620_PWM_PERIOD_NS;

	state->polarity = PWM_POLARITY_NORMAL;



	return 0;

}

drivers/pwm/pwm-meson.c

+8 −0
Original line number Diff line number Diff line
@@ -162,6 +162,12 @@ static int meson_pwm_calc(struct meson_pwm *meson, struct pwm_device *pwm, 
	duty = state->duty_cycle;

	period = state->period;



	/*

	 * Note this is wrong. The result is an output wave that isn't really

	 * inverted and so is wrongly identified by .get_state as normal.

	 * Fixing this needs some care however as some machines might rely on

	 * this.

	 */

	if (state->polarity == PWM_POLARITY_INVERSED)

		duty = period - duty;
@@ -358,6 +364,8 @@ static int meson_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, 
		state->duty_cycle = 0;

	}



	state->polarity = PWM_POLARITY_NORMAL;



	return 0;

}