Re: [PATCH 1/2] video: ssd1307fb: Print PWM period using 64-bit format specifier

From: Uwe Kleine-KÃnig
Date: Wed Jun 17 2020 - 13:30:42 EST


On Wed, Jun 17, 2020 at 09:18:34AM +0200, Geert Uytterhoeven wrote:
> Hi Thierry,
>
> On Mon, Jun 15, 2020 at 4:17 PM Thierry Reding <thierry.reding@xxxxxxxxx> wrote:
> > The PWM core will soon change the duty cycle and period of PWMs to 64
> > bits to allow for a broader range of values. Use a 64-bit format
> > specifier to avoid a warning when that change is made.
> >
> > Signed-off-by: Thierry Reding <thierry.reding@xxxxxxxxx>
>
> > --- a/drivers/video/fbdev/ssd1307fb.c
> > +++ b/drivers/video/fbdev/ssd1307fb.c
> > @@ -312,7 +312,7 @@ static int ssd1307fb_init(struct ssd1307fb_par *par)
> > /* Enable the PWM */
> > pwm_enable(par->pwm);
> >
> > - dev_dbg(&par->client->dev, "Using PWM%d with a %dns period.\n",
> > + dev_dbg(&par->client->dev, "Using PWM%d with a %lluns period.\n",
> > par->pwm->pwm, pwm_get_period(par->pwm));
> > }
>
> This change must be done together with changing the return type of
> pwm_get_period(), else you will get a compiler warning, and will print a
> bogus value.

Right, or we must change to passing (unsigned long
long)pwm_get_period(par->pwm), then change the prototype and then drop
the cast again.

Best regards
Uwe

--
Pengutronix e.K. | Uwe Kleine-König |
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