Re: [PATCH] rtc: armada38x: zalloc + calloc to single allocation

[Rosen Penev]

On Thu, Mar 5, 2026 at 12:41 AM Gregory CLEMENT
<gregory.clement@xxxxxxxxxxx> wrote:
>
> Rosen Penev <rosenp@xxxxxxxxx> writes:
>
> > Use a flexible array member to simplify allocation.
> >
>
> I must admit that I didn't know struct_size(), it is a nice helper!
There's kzalloc_flex that's even nicer. Has no devm version yet.
>
> Reviewed-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxx>
>
> Thanks,
>
> Gregory
> > Signed-off-by: Rosen Penev <rosenp@xxxxxxxxx>
> > ---
> >  drivers/rtc/rtc-armada38x.c | 9 ++-------
> >  1 file changed, 2 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/rtc/rtc-armada38x.c b/drivers/rtc/rtc-armada38x.c
> > index 713fa0d077cd..245290ae1a8d 100644
> > --- a/drivers/rtc/rtc-armada38x.c
> > +++ b/drivers/rtc/rtc-armada38x.c
> > @@ -72,8 +72,8 @@ struct armada38x_rtc {
> >       spinlock_t          lock;
> >       int                 irq;
> >       bool                initialized;
> > -     struct value_to_freq *val_to_freq;
> >       const struct armada38x_rtc_data *data;
> > +     struct value_to_freq val_to_freq[];
> >  };
> >
> >  #define ALARM1       0
> > @@ -490,18 +490,13 @@ static __init int armada38x_rtc_probe(struct platform_device *pdev)
> >  {
> >       struct armada38x_rtc *rtc;
> >
> > -     rtc = devm_kzalloc(&pdev->dev, sizeof(struct armada38x_rtc),
> > +     rtc = devm_kzalloc(&pdev->dev, struct_size(rtc, val_to_freq, SAMPLE_NR),
> >                           GFP_KERNEL);
> >       if (!rtc)
> >               return -ENOMEM;
> >
> >       rtc->data = of_device_get_match_data(&pdev->dev);
> >
> > -     rtc->val_to_freq = devm_kcalloc(&pdev->dev, SAMPLE_NR,
> > -                             sizeof(struct value_to_freq), GFP_KERNEL);
> > -     if (!rtc->val_to_freq)
> > -             return -ENOMEM;
> > -
> >       spin_lock_init(&rtc->lock);
> >
> >       rtc->regs = devm_platform_ioremap_resource_byname(pdev, "rtc");
> > --
> > 2.53.0
> >
>
> --
> Grégory CLEMENT, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com