Re: [PATCH 07/11] ARM: dts: lpc: Remove NOMMU platform support

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Unintended removal of the MMU-capable LPC32xx platform under the false premise of removing NOMMU support, along with an inaccurate commit message.
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commit d19b47e78b74813c8413198ab7ec32784181d8d8
Author: Frank Li <Frank.Li@nxp.com>
Subject: ARM: dts: lpc: Remove NOMMU platform support

This commit removes the arch/arm/boot/dts/nxp/lpc directory, stating the
intention is to remove unused NOMMU platform support. It drops the build
targets for LPC platforms to simplify the codebase.

>     ARM: dts: lpc: Remove NOMMU platform support
>     
>     Commercial users and hardware vendors migrated to Zephyr or other RTOS
>     solutions years ago, leaving the NOMMU platform support effectively
>     unused and unmaintained.
>     
>     Remove the obsolete support to reduce maintenance burden and simplify the
>     i.MX platform code.

[Severity: High]
Does this commit unintentionally remove the MMU-capable LPC32xx platform?
While the LPC18xx and LPC43xx series are Cortex-M NOMMU parts, the LPC32xx
series uses an ARM926EJ-S processor, which features a full MMU and runs a
standard Linux kernel.

This mistake appears to cascade through the rest of the patch series, where
mach-lpc32xx is also deleted under the same 'NOMMU' premise.

Also, this isn't a bug, but there appears to be a copy-paste error in the
commit message where it mentions simplifying the "i.MX platform code" instead
of LPC.

> diff --git a/arch/arm/boot/dts/nxp/lpc/Makefile b/arch/arm/boot/dts/nxp/lpc/Makefile
> deleted file mode 100644
> index 56b9a0ebb9179..0000000000000
> --- a/arch/arm/boot/dts/nxp/lpc/Makefile
> +++ /dev/null
> @@ -1,9 +0,0 @@
> -# SPDX-License-Identifier: GPL-2.0
> -dtb-$(CONFIG_ARCH_LPC18XX) += \
> -	lpc4337-ciaa.dtb \
> -	lpc4350-hitex-eval.dtb \
> -	lpc4357-ea4357-devkit.dtb \
> -	lpc4357-myd-lpc4357.dtb
> -dtb-$(CONFIG_ARCH_LPC32XX) += \
> -	lpc3250-ea3250.dtb \
> -	lpc3250-phy3250.dtb

[Severity: High]
Does the removal of these targets improperly disable the LPC32XX platform,
which relies on an MMU-capable core?

> diff --git a/arch/arm/boot/dts/nxp/lpc/lpc32xx.dtsi b/arch/arm/boot/dts/nxp/lpc/lpc32xx.dtsi
> deleted file mode 100644
> index e94df78def18a..0000000000000
> --- a/arch/arm/boot/dts/nxp/lpc/lpc32xx.dtsi
> +++ /dev/null
> @@ -1,540 +0,0 @@
[ ... ]
> -	cpus {
> -		#address-cells = <1>;
> -		#size-cells = <0>;
> -
> -		cpu@0 {
> -			compatible = "arm,arm926ej-s";
> -			device_type = "cpu";
> -			reg = <0x0>;
> -		};
> -	};

[Severity: High]
Since this node defines cpu@0 as an ARM926EJ-S, a core that features a full
MMU, does this contradict the commit's justification for removing this
platform as 'NOMMU'?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260619-dts_cleanup_arm_mcore-v1-0-0101795a2662@nxp.com?part=7