[PATCH v2 3/3] ARM: dts: broadcom: Use CFE CPU bring-up on the XG6846B

[William Zhang]

Hi Linus,

On Sat, Oct 17, 2026 at 12:47 AM Linus Walleij <linusw at kernel.org> wrote:
>
> The XG6846B boots through CFE, which parks CPU1 in a holding pen and does
> not provide PSCI. Chain-loading mainline U-Boot and starting Linux with
> "go" does not install a PSCI implementation either. The working PSCI
> interface in newer GenXOS firmware belongs to a different boot stack.
>
> Disable the inherited PSCI node on this board so Linux does not issue
> SMCs to an interface that is absent. Remove the CPU PSCI enable-method
> properties and use the board-specific CFE SMP operations. Describe the
> CFE mailbox in CPU1's cpu-release-addr property. Keep both CPU nodes
> enabled and leave the SoC's PSCI defaults available to other boards.
>
> Assisted-by: LLM
> Signed-off-by: Linus Walleij <linusw at kernel.org>
> ---
>  arch/arm/boot/dts/broadcom/bcm6846-genexis-xg6846b.dts | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
>
> diff --git a/arch/arm/boot/dts/broadcom/bcm6846-genexis-xg6846b.dts b/arch/arm/boot/dts/broadcom/bcm6846-genexis-xg6846b.dts
> index 6cb221dca0ac..1b85e382c70c 100644
> --- a/arch/arm/boot/dts/broadcom/bcm6846-genexis-xg6846b.dts
> +++ b/arch/arm/boot/dts/broadcom/bcm6846-genexis-xg6846b.dts
> @@ -56,6 +56,20 @@ button-restart {
>         };
>  };
>
> +/* CFE parks CPU1 in its holding pen and does not provide PSCI. */
> +&{/psci} {
> +       status = "disabled";
> +};
> +
> +&CA7_0 {
> +       /delete-property/ enable-method;
I sugguest to override the psci enable-method with
     enable-method = "brcm,bca-smp"
for this generic bca armv7 smp method.  And you can add this smp method
handler in board_bcmbca.c (which you already have the main implementation) to
make it work for all future bcmbca v7 devices that do not use psci through
this dts setting.
> +};
> +
> +&CA7_1 {
> +       /delete-property/ enable-method;
> +       cpu-release-addr = <0xff800568>;
> +};
> +
>  &gpio0 {
>         status = "okay";
>  };
>
> --
> 2.56.0
>
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