Re: [PATCH v7 2/5] arm64: dts: qcom: Add Kalambo SoC

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Missing disablement of bwmon_cluster0 after CPU cluster 0 removal, leading to a synchronous external abort upon driver probe.
--

commit 917eea48188cf7e004e9ea44ee5963d8c898f1e5
Author: Gopikrishna Garmidi <gopikrishna.garmidi@oss.qualcomm.com>

arm64: dts: qcom: Add Kalambo SoC

Introduce support for the Qualcomm Kalambo SoC. It is derived from Mahua
with CPU cluster 0 (cpu0-cpu5) removed, leaving only cluster 1 (cpu6-cpu11).
The surviving cluster is re-added in the cpu-map as cluster0.

> diff --git a/arch/arm64/boot/dts/qcom/kalambo.dtsi b/arch/arm64/boot/dts/qcom/kalambo.dtsi
> new file mode 100644
> index 0000000000000..8e2077d9d0a8a
> --- /dev/null
> +++ b/arch/arm64/boot/dts/qcom/kalambo.dtsi
> @@ -0,0 +1,119 @@
> +// SPDX-License-Identifier: BSD-3-Clause
> +/*
> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
> + */
> +
> +#include "mahua.dtsi"
> +
> +/delete-node/ &cluster0_pd;
> +/delete-node/ &cpu_map;
> +/delete-node/ &cpu0;
> +/delete-node/ &cpu1;
> +/delete-node/ &cpu2;
> +/delete-node/ &cpu3;
> +/delete-node/ &cpu4;
> +/delete-node/ &cpu5;
> +/delete-node/ &cpu_pd0;
> +/delete-node/ &cpu_pd1;
> +/delete-node/ &cpu_pd2;
> +/delete-node/ &cpu_pd3;
> +/delete-node/ &cpu_pd4;
> +/delete-node/ &cpu_pd5;
> +/delete-node/ &cpu_scp_lpri1;

[Severity: High]
Since cluster 0 components are explicitly deleted here, does bwmon_cluster0
also need to be disabled?

The bwmon_cluster0 hardware is enabled by default in glymur.dtsi. If it
remains enabled here, the qcom,sdm845-bwmon driver will attempt to probe it
during boot. Would this result in a Synchronous External Abort (bus error)
and a kernel panic when the driver attempts memory-mapped I/O on the missing
hardware?

If bwmon_cluster0 is physically absent on Kalambo but cannot be deleted
entirely because it contains the shared cpu_bwmon_opp_table used by
bwmon_cluster1, should its status be overridden to disabled instead?

&bwmon_cluster0 {
	status = "disabled";
};

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260909-b4-kalambo-crd-v7-0-f5685804478a@oss.qualcomm.com?part=2