Re: [PATCH] pwm: sun4i: Initialize variables before use

["Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>]

Hello Thierry,

On Mon, Jan 20, 2020 at 03:32:06PM +0100, Thierry Reding wrote:
> GCC can't always determine that the duty, period and prescaler values
> are initialized when returning from sun4i_pwm_calculate(), so help out a
> little by initializing them to 0.

Is it worth mentioning the gcc version you're using?

> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
> ---
>  drivers/pwm/pwm-sun4i.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
> index 0decc7cde133..3e3efa6c768f 100644

I don't find this object (0decc7cde133) in my tree or next. Which
version is this?

> --- a/drivers/pwm/pwm-sun4i.c
> +++ b/drivers/pwm/pwm-sun4i.c
> @@ -234,9 +234,9 @@ static int sun4i_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
>  {
>  	struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip);
>  	struct pwm_state cstate;
> -	u32 ctrl, duty, period, val;
> +	u32 ctrl, duty = 0, period = 0, val;

+     u32 ctrl, uninitialized_var(duty), uninitialized_var(period), val;

should fix the warnings, too, and additionally explicitly documents that
it's just the compiler that doesn't see there is no problem.

Best regards
Uwe

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Pengutronix e.K.                           | Uwe Kleine-König            |
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