Re: [PATCH net-next v4 13/14] net: dsa: rzn1-a5psw: Add support for RZ/T2H Ethernet switch

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] net: dsa: rzn1-a5psw: commit message mismatch on management port frame length
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commit 0cd79c8af56dc7e73238cc6afe8332ba3c3c215a
Author: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

net: dsa: rzn1-a5psw: Add support for RZ/T2H Ethernet switch

This commit adds device tree match data and switch configuration for the
Renesas RZ/T2H Ethernet switch in the rzn1-a5psw DSA driver.

>     net: dsa: rzn1-a5psw: Add support for RZ/T2H Ethernet switch
>     
>     Add device tree match data and configuration for the Renesas RZ/T2H
>     SoC Ethernet switch. The RZ/T2H uses the same A5PSW switch IP as RZ/N1
>     but with four ports, the DSA tagging protocol `DSA_TAG_PROTO_RZT2H_ETHSW`,
>     and an additional 8-byte management port frame length adjustment.
>     
>     This prepares the driver to handle RZ/T2H and compatible RZ/N2H
>     Ethernet switch instances.
>     
>     Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> 
> diff --git a/drivers/net/dsa/rzn1_a5psw.c b/drivers/net/dsa/rzn1_a5psw.c
> index f3eb8646dea5b..66b1556864743 100644
> --- a/drivers/net/dsa/rzn1_a5psw.c
> +++ b/drivers/net/dsa/rzn1_a5psw.c
> @@ -1338,6 +1338,14 @@ static void a5psw_shutdown(struct platform_device *pdev)
>  	platform_set_drvdata(pdev, NULL);
>  }
>  
> +static const struct a5psw_of_data rzt2h_of_data = {
> +	.nports = 4,
> +	.npcs = 3,
> +	.cpu_port = 3,
> +	.tag_proto = DSA_TAG_PROTO_RZT2H_ETHSW,
> +	.management_port_fixed_frame_len = 0x3fff,
> +};

[Severity: Medium]
As reported by Sashiko on v3 [1], is the commit message description of an
"additional 8-byte management port frame length adjustment" still accurate?

In drivers/net/dsa/rzn1_a5psw.c, rzt2h_of_data sets
management_port_fixed_frame_len to 0x3fff (16383 bytes), which programs
A5PSW_FRM_LENGTH(port) on the CPU port to a fixed maximum value in
a5psw_setup() and skips MTU-based updates on the CPU port in
a5psw_port_change_mtu(), rather than applying an 8-byte adjustment.

Should the commit message be updated to match the fixed frame length
configuration in rzt2h_of_data?

[1] https://lore.kernel.org/r/20261014131906.990077-13-prabhakar.mahadev-lad.rj@bp.renesas.com

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261104182105.1102555-1-prabhakar.mahadev-lad.rj@bp.renesas.com?part=13