Re: [PATCH v2 4/4] can: rcar_canfd: Add RZ/T2H support

[Geert Uytterhoeven]

Hi Prabhakar,

On Thu, 8 Jan 2026 at 11:13, Lad, Prabhakar <prabhakar.csengg@xxxxxxxxx> wrote:
> On Wed, Jan 7, 2026 at 4:37 PM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
> > On Tue, 30 Dec 2025 at 12:58, Prabhakar <prabhakar.csengg@xxxxxxxxx> wrote:
> > > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> > >
> > > The CAN-FD IP on the RZ/T2H SoC is similar to R-Car Gen4, but differs in
> > > the AFLPN and CFTML bits and supports two channels with eight interrupts.
> > >
> > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> >
> > Thanks for your patch!
> >
> > LGTM, so
> > Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> >
> > However, compared to other SoCs, CFDCnNCFG.NSJW[6:0] has:
> >
> >     0x00: Setting prohibited
> >
> Sharp eye!

I knew what I had to look for ;-)

This one was indeed hard to compare with other SoCs, as the structure
is completely different. For e.g. RZ/V2H and RZ/G3E, I could just use
diffpdf, restricted to the pages I am interested in.

Still need to enhance diffpdf with shift up/down buttons, so I don't
have to adjust the page numbers manually when a few lines are suddenly
moved to a new page...

> > Perhaps this is a documentation issue, as the same limitation was
> > dropped in RZ/V2H Hardware User Manual Rev.1.30?
> > Linux also has no can_bittiming_const.sjw_min field.
> >
> I've notified the HW team to get it clarified.

Thanks!

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds