Re: [PATCH 1/5] net: dsa: microchip: Add fallback Micrel compatibles

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Driver binding conflict due to duplicated compatible strings
--

commit 602050a194c8c1c059a85fb34c0d360b801f20f8
Author: Linus Walleij <linusw@kernel.org>

net: dsa: microchip: Add fallback Micrel compatibles

Because of forking paths when Micrel was acquired by Microchip,
two devices also exist with the micrel,* prefix bindings.
Add these to the KSZ SPI driver so users can use the more capable
driver.

> diff --git a/drivers/net/dsa/microchip/ksz_spi.c b/drivers/net/dsa/microchip/ksz_spi.c
> index d8001734b0574..c38eda65aaf24 100644
> --- a/drivers/net/dsa/microchip/ksz_spi.c
> +++ b/drivers/net/dsa/microchip/ksz_spi.c
> @@ -224,6 +224,21 @@ static void ksz_spi_shutdown(struct spi_device *spi)
>  }
>  
>  static const struct of_device_id ksz_dt_ids[] = {
> +	/*
> +	 * Legacy Micrel bindings. In 2015 Microchip acquired
> +	 * Micrel which is the originator of the KSZ series, and
> +	 * devices branded for Micrel already existed, as well as
> +	 * some device tree bindings. These two products are identical
> +	 * to the same Microchip products.
> +	 */
> +	{
> +		.compatible = "micrel,ksz8864",
> +		.data = &ksz_switch_chips[KSZ8864]
> +	},
> +	{
> +		.compatible = "micrel,ksz8795",
> +		.data = &ksz_switch_chips[KSZ8795]
> +	},

Does this create a driver binding conflict since these exact compatible
strings are actively claimed by ks8995_spi_of_match[] in
drivers/net/dsa/ks8995.c?

Having two drivers claim the same hardware ID without mutual Kconfig
exclusion leads to a non-deterministic driver binding race, breaking
bisectability.

While later commits in the series resolve this (commit "net: dsa:
microchip: Support Microchip KSZ8995XA / KS8995XA" adds the Kconfig
dependency, and commit "net: dsa: ks8995: Delete surplus driver"
removes the old driver), shouldn't the mutual exclusion be introduced
in this patch to ensure the commit history remains fully bisectable?

>  	{
>  		.compatible = "microchip,ksz8463",
>  		.data = &ksz_switch_chips[KSZ8463]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260516-ks8995-to-ksz8-v1-0-70d0ef4aa5f4@kernel.org?part=1