Re: [PATCH] thermal/core: Make 'forced_passive' as obsolete candidate

[Daniel Lezcano <daniel.lezcano@linaro.org>]

On 08/12/2020 16:30, Daniel Lezcano wrote:
> The passive file in sysfs forces the usage of a passive trip point set
> by the userspace when a broken BIOS does not provide the mitigation
> temperature for such thermal zone. The hardware evolved a lot since
> 2008 as a good thermal management is no longer an option.
> 
> Linux on the other side also provides now a way to load fixed ACPI
> table via the option ACPI_TABLE_UPGRADE, so additionnal trip point
> could be added there.
> 
> Set the option obsolete and plan to remove it, so the corresponding
> code can be removed from the core code and allow more cleanups the
> thermal framework deserves.
> 
> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> ---

Is there any concern about this change ?

>  Documentation/ABI/obsolete/sysfs-thermal-passive | 13 +++++++++++++
>  drivers/thermal/thermal_sysfs.c                  |  2 ++
>  2 files changed, 15 insertions(+)
>  create mode 100644 Documentation/ABI/obsolete/sysfs-thermal-passive
> 
> diff --git a/Documentation/ABI/obsolete/sysfs-thermal-passive b/Documentation/ABI/obsolete/sysfs-thermal-passive
> new file mode 100644
> index 000000000000..2510724cc165
> --- /dev/null
> +++ b/Documentation/ABI/obsolete/sysfs-thermal-passive
> @@ -0,0 +1,13 @@
> +What:		/sys/class/thermal/thermal_zone*/passive
> +Date:		December 2008
> +KernelVersion:	2.6.28
> +Contact:	Daniel Lezcano <daniel.lezcano@linaro.org>
> +Description:
> +
> +  The passive file in sysfs forces the usage of a passive trip point
> +  set by the userspace when a broken BIOS does not provide the
> +  mitigation temperature for such thermal zone. However, the Linux
> +  kernel evolved a lot since 2008 as well as the hardware and it is
> +  able to manage correctly the thermal envelope. It does also provide
> +  a way to load fixed ACPI table via the option ACPI_TABLE_UPGRADE, so
> +  additionnal trip point could be added there.
> diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c
> index 0866e949339b..578099b520b1 100644
> --- a/drivers/thermal/thermal_sysfs.c
> +++ b/drivers/thermal/thermal_sysfs.c
> @@ -232,6 +232,8 @@ passive_store(struct device *dev, struct device_attribute *attr,
>  	if (state && state < 1000)
>  		return -EINVAL;
>  
> +	pr_warn("%s: Consider the 'passive' option obsolete\n", tz->type);
> +
>  	if (state && !tz->forced_passive) {
>  		if (!tz->passive_delay)
>  			tz->passive_delay = 1000;
> 


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