[PATCH v3 1/5] lib: utils/irqchip: plic: Fix the off-by-one error in priority save/restore helpers

[Bin Meng]

On Sun, Dec 11, 2022 at 6:08 PM Andreas Schwab <schwab at linux-m68k.org> wrote:
>
> On Dez 11 2022, Bin Meng wrote:
>
> > diff --git a/lib/utils/irqchip/plic.c b/lib/utils/irqchip/plic.c
> > index 73d7788..4df9020 100644
> > --- a/lib/utils/irqchip/plic.c
> > +++ b/lib/utils/irqchip/plic.c
> > @@ -38,13 +38,13 @@ static void plic_set_priority(const struct plic_data *plic, u32 source, u32 val)
> >
> >  void plic_priority_save(const struct plic_data *plic, u8 *priority)
> >  {
> > -     for (u32 i = 0; i < plic->num_src; i++)
> > +     for (u32 i = 1; i <= plic->num_src; i++)
> >               priority[i] = plic_get_priority(plic, i);
>
> That needs to adjust the index into the priority array.

Does that help anything? It just confuses people more.

I added function parameter descriptions in patch 2 to make it crystal
clear, that the priority array needs to include interrupt source 0.

>
> >  void plic_priority_restore(const struct plic_data *plic, const u8 *priority)
> >  {
> > -     for (u32 i = 0; i < plic->num_src; i++)
> > +     for (u32 i = 1; i <= plic->num_src; i++)
> >               plic_set_priority(plic, i, priority[i]);
>
> Likewise.
>

Regards,
Bin