Re: [PATCH v2 2/2] firmware: meson: sm: make power-off work on S4

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [Low] firmware: meson: duplicate meson-sm prefix in
  meson_sm_power_off_prepare()
--

commit 0142b0300be6322393138fbe4dbbf32405872dee
Author: Christian Stefan Kövér-Draxl <ckoever@outlook.de>

firmware: meson: sm: make power-off work on S4

This commit registers a power-off prepare handler for Amlogic S4 that
offlines secondary CPUs and sets the firmware shutdown flag before PSCI
SYSTEM_OFF.

> diff --git a/drivers/firmware/meson/meson_sm.c b/drivers/firmware/meson/meson_sm.c
> index ab9751a59b552..de0c8e809c516 100644
> --- a/drivers/firmware/meson/meson_sm.c
> +++ b/drivers/firmware/meson/meson_sm.c

[ ... ]

> @@ -303,6 +306,28 @@ static struct attribute *meson_sm_sysfs_attrs[] = {
>  };
>  ATTRIBUTE_GROUPS(meson_sm_sysfs);
>  
> +/*
> + * The S4 firmware implements PSCI SYSTEM_OFF as DDR self-refresh: on the
> + * power key it jumps back to the kernel instead of booting, which hangs the
> + * board. Setting the shutdown flag first makes it cold-boot instead, and the
> + * secondary CPUs must have been taken down through PSCI CPU_OFF beforehand,
> + * otherwise the wake-up path hangs as well. machine_power_off() only parks
> + * them, so offline them here, while CPU hotplug still works.
> + */
> +static int meson_sm_power_off_prepare(struct sys_off_data *data)
> +{
> +	unsigned int cpu, primary = cpumask_first(cpu_online_mask);
> +
> +	for_each_online_cpu(cpu) {
> +		if (cpu != primary && remove_cpu(cpu))
> +			pr_warn("meson-sm: failed to stop CPU%u\n", cpu);

[Severity: Low]
Does this duplicate the "meson-sm: " prefix in the kernel log?
drivers/firmware/meson/meson_sm.c already defines pr_fmt(fmt) as
"meson-sm: " fmt at the top of the file.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261106101854.46569-1-christian.koever-draxl@student.uibk.ac.at?part=2

_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic