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From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: Tue, 30 Jan 2024 14:05:47 +0100
Message-ID: <CAMuHMdVu+VNW56VYkJs2w-S=1372_ZL6K2LQGKoR9vugpR+Z-w@mail.gmail.com>
Subject: Re: [PATCH 1/5] dt-bindings: interrupt-controller:
 renesas,rzg2l-irqc: Document RZ/Five SoC
To: "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
Cc: Conor Dooley <conor@kernel.org>, Thomas Gleixner <tglx@linutronix.de>, 
	Rob Herring <robh+dt@kernel.org>, 
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>, Conor Dooley <conor+dt@kernel.org>, 
	Magnus Damm <magnus.damm@gmail.com>, linux-renesas-soc@vger.kernel.org, 
	devicetree@vger.kernel.org, linux-riscv@lists.infradead.org, 
	linux-kernel@vger.kernel.org, Biju Das <biju.das.jz@bp.renesas.com>, 
	Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>, 
	Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
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Hi Prabhakar,

On Tue, Jan 30, 2024 at 1:59=E2=80=AFPM Lad, Prabhakar
<prabhakar.csengg@gmail.com> wrote:
> On Tue, Jan 30, 2024 at 11:13=E2=80=AFAM Geert Uytterhoeven
> <geert@linux-m68k.org> wrote:
> > On Mon, Jan 29, 2024 at 6:30=E2=80=AFPM Conor Dooley <conor@kernel.org>=
 wrote:
> > > On Mon, Jan 29, 2024 at 03:16:14PM +0000, Prabhakar wrote:
> > > > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > > >
> > > > Document RZ/Five (R9A07G043F) IRQC bindings. The IRQC block on RZ/F=
ive SoC
> > > > is almost identical to one found on the RZ/G2L SoC with below diffe=
rences,
> > > > * Additional BUS error interrupt
> > > > * Additional ECCRAM error interrupt
> > > > * Has additional mask control registers for NMI/IRQ/TINT
> > > >
> > > > Hence new compatible string "renesas,r9a07g043f-irqc" is added for =
RZ/Five
> > > > SoC.
> > > >
> > > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.c=
om>
> >
> > > > --- a/Documentation/devicetree/bindings/interrupt-controller/renesa=
s,rzg2l-irqc.yaml
> > > > +++ b/Documentation/devicetree/bindings/interrupt-controller/renesa=
s,rzg2l-irqc.yaml
> > > > @@ -134,6 +141,12 @@ properties:
> > > >        - const: tint30
> > > >        - const: tint31
> > > >        - const: bus-err
> > > > +      - const: eccram0-tie1
> > > > +      - const: eccram0-tie2
> > > > +      - const: eccram0-ovf
> > > > +      - const: eccram1-tie1
> > > > +      - const: eccram1-tie2
> > > > +      - const: eccram1-ovf
> >
> > Why not use the naming from the docs (all 6 include "ti")?
> > EC7TIE1_0, EC7TIE2_0, EC7TIOVF_0, EC7TIE1_1, EC7TIE2_1, EC7TIOVF_1
> > =3D> ec7tie1-0, ec7tie2-0, ec7tiovf-0, ...?
> >
> Agreed.
>
> > > I think the restrictions already in the file become incorrect with th=
is
> > > patch:
> > >   - if:
> > >       properties:
> > >         compatible:
> > >           contains:
> > >             enum:
> > >               - renesas,r9a07g043u-irqc
> > >               - renesas,r9a08g045-irqc
> > >     then:
> > >       properties:
> > >         interrupts:
> > >           minItems: 42
> > >         interrupt-names:
> > >           minItems: 42
> > >       required:
> > >         - interrupt-names
> > >
> > > This used to require all 42 interrupts for the two compatibles here
> > > and at least the first 41 otherwise. Now you've increased the number =
of
> > > interrupts to 48 thereby removing the upper limits on the existing
> > > devices.
> >
> > I'm gonna repeat (and extend) my question from [1]: How come we thought
> > RZ/G2L and RZ/V2L do not have the bus error and ECCRAM interrupts?
> >
> Hmm not sure how this was missed earlier.
>
> > Looks like most of the conditional handling can be removed (see below).
> >
> > > Given the commit message, I figure that providing 48 interrupts for
> > > (at least some of) those devices would be incorrect?
> >
> > Looks like all of RZ/G2L{,C}, RZ/V2L, RZ/G2UL, and RZ/Five support
> > all 48 interrupts.  RZ/G3S lacks the final three for ECCRAM1.
> >
> Agreed for RZ/G2L{,C}, RZ/V2L, RZ/G2UL, and RZ/Five, but for RZ/G3S it
> becomes tricky the interrupts for ECCRAM0/1 are combined hence they
> have just 3 interrupts. How do you propose the above interrupt naming?

I guess it doesn't hurt to have an index 0 on a part that has only a
single set?

Alternatives would be to
  1. Drop the index completely on RZ/G3S, complicating bindings and
     driver,
  1. Drop the index for the first set, and use index 2 for the second set,
     causing the names to differ even more on parts with 2 sets.

Gr{oetje,eeting}s,

                        Geert

--=20
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k=
org

In personal conversations with technical people, I call myself a hacker. Bu=
t
when I'm talking to journalists I just say "programmer" or something like t=
hat.
                                -- Linus Torvalds