Messages in this thread | | | Date | Thu, 26 Jan 2017 12:16:18 +0000 | From | Lee Jones <> | Subject | Re: [PATCH] pwm: fix undefined behavior in stm32_pwm_apply |
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On Wed, 25 Jan 2017, Arnd Bergmann wrote:
> The stm32_pwm_apply randomly sets the polarity or doesn't, > as pointed out by this gcc warning: > > drivers/pwm/pwm-stm32.c: In function 'stm32_pwm_apply': > drivers/pwm/pwm-stm32.c:204:33: error: 'curstate.polarity' may be used uninitialized in this function [-Werror=maybe-uninitialized] > > I assume it was meant to compare the new state to the current > state rather than an uninitialized stack variable, so let's > do that instead. > > Fixes: bafffb6e7bd1 ("pwm: Add driver for STM32 plaftorm") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > drivers/pwm/pwm-stm32.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-)
Fix from the author already applied.
> diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c > index ce6232ebefe1..6139512aab7b 100644 > --- a/drivers/pwm/pwm-stm32.c > +++ b/drivers/pwm/pwm-stm32.c > @@ -189,7 +189,6 @@ static void stm32_pwm_disable(struct stm32_pwm *priv, int ch) > static int stm32_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, > struct pwm_state *state) > { > - struct pwm_state curstate; > bool enabled; > struct stm32_pwm *priv = to_stm32_pwm_dev(chip); > int ret; > @@ -201,7 +200,7 @@ static int stm32_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, > return 0; > } > > - if (state->polarity != curstate.polarity) > + if (state->polarity != pwm->state.polarity) > stm32_pwm_set_polarity(priv, pwm->hwpwm, state->polarity); > > ret = stm32_pwm_config(priv, pwm->hwpwm,
-- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog
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