Re: [PATCH net-next 10/12] can: rcar_canfd: Document that RZ/G3S has no Classical CAN mode

[netdev-bot+sashiko@kernel.org]

Thank you for your contribution! Sashiko AI review found more severe
issue(s) in other patches of this series. This mail is only an FYI, in case
you want to address the nit picks below when you respin.

Low priority / nit picks for your consideration:

- [Low] The patch fixes only half of the header comment in
  drivers/net/can/rcar/rcar_canfd.c.

--

can: rcar_canfd: Document that RZ/G3S has no Classical CAN mode

This patch changes the header comments in the R-Car CAN FD driver to say
that RZ/G3S does not support Classical CAN (CAN 2.0) only mode. It
matches the corresponding dt-bindings update. There is no functional
change.

Link: https://patch.msgid.link/20261021-canfd_rzg3l-v6-2-b4abfdba8e70@bp.renesas.com

> diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
> index 4f5cdfa8211da..072987316cc75 100644
> --- a/drivers/net/can/rcar/rcar_canfd.c
> +++ b/drivers/net/can/rcar/rcar_canfd.c
> @@ -6,7 +6,7 @@
>  
>  /* The R-Car CAN FD controller can operate in either one of the below two modes
>   *  - CAN FD only mode
> - *  - Classical CAN (CAN 2.0) only mode
> + *  - Classical CAN (CAN 2.0) only mode (Except RZ/G3S)
>   *
>   * This driver puts the controller in CAN FD only mode by default. In this
>   * mode, the controller acts as a CAN FD node that can also interoperate with

[Severity: Low]
This isn't a bug, but should the paragraph just below this one in the same
header comment get the RZ/G3S exception too? The patch leaves it as is:

drivers/net/can/rcar/rcar_canfd.c:
 * To switch the controller to Classical CAN (CAN 2.0) only mode, add
 * "renesas,no-can-fd" optional property to the device tree node. A h/w reset is
 * also required to switch modes.

The renesas,rcar-canfd.yaml binding does not allow this property on RZ/G3S.
The allOf branch for renesas,r9a08g045-canfd has:

    then:
      properties:
        renesas,no-can-fd: false
        renesas,fd-only: false

So the comment now says Classical CAN mode is not available on RZ/G3S, but
the next paragraph still tells readers to add renesas,no-can-fd, without
naming any SoC that cannot use it.

Later in the series, "can: rcar_canfd: Add support for Renesas RZ/G3L"
changes only the line above to "(Except RZ/G3{L,S})" and leaves this
paragraph as it is.

Could the instruction paragraph also say that renesas,no-can-fd must not
be used on RZ/G3S?

[ ... ]

-- 
Sashiko AI review · https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20261110115112.3807247-2-mkl%40pengutronix.de