[PATCH] ACPI: thermal: extend the acpi maximum handles for _PSL method

[PATCH] ACPI: thermal: extend the acpi maximum handles for _PSL method

[Ivan Hu]

Several platforms encountered the following kernel message:
ACPI: \_TZ_.BATZ: Invalid passive threshold

This issue arises due to the failure of the acpi_evaluate_reference function
in drivers/acpi/thermal.c while evaluating the ACPI _PSL method.

status = acpi_evaluate_reference(tz->device->handle, "_PSL",
			 NULL, &devices);
if (ACPI_FAILURE(status)) {
	acpi_handle_info(tz->device->handle,
			 "Invalid passive threshold\n");
	tz->trips.passive.valid = false;
} else {
	tz->trips.passive.valid = true;
}

However, the root cause lies in the _PSL method returning packages with a count
exceeding ACPI_MAX_HANDLES in acpi_evaluate_reference.

As per the ACPI specification, the _PSL (Passive List) method is defined under
a thermal zone and evaluates to a list of processor objects to be used for
passive cooling. And it will return a variable-length Package containing a list
of References to processor objects.

Signed-off-by: Ivan Hu <ivan.hu@canonical.com>
---
 include/acpi/acpi_bus.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 23fbe4a16972..dc7b38826113 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -13,7 +13,7 @@
 #include <linux/property.h>
 
 /* TBD: Make dynamic */
-#define ACPI_MAX_HANDLES	10
+#define ACPI_MAX_HANDLES	32
 struct acpi_handle_list {
 	u32 count;
 	acpi_handle handles[ACPI_MAX_HANDLES];
-- 
2.34.1

Re: [PATCH] ACPI: thermal: extend the acpi maximum handles for _PSL method

[Rafael J. Wysocki]

On Wed, Aug 9, 2023 at 11:44 AM Ivan Hu <ivan.hu@canonical.com> wrote:
>
> Several platforms encountered the following kernel message:
> ACPI: \_TZ_.BATZ: Invalid passive threshold
>
> This issue arises due to the failure of the acpi_evaluate_reference function
> in drivers/acpi/thermal.c while evaluating the ACPI _PSL method.
>
> status = acpi_evaluate_reference(tz->device->handle, "_PSL",
>                          NULL, &devices);
> if (ACPI_FAILURE(status)) {
>         acpi_handle_info(tz->device->handle,
>                          "Invalid passive threshold\n");
>         tz->trips.passive.valid = false;
> } else {
>         tz->trips.passive.valid = true;
> }
>
> However, the root cause lies in the _PSL method returning packages with a count
> exceeding ACPI_MAX_HANDLES in acpi_evaluate_reference.
>
> As per the ACPI specification, the _PSL (Passive List) method is defined under
> a thermal zone and evaluates to a list of processor objects to be used for
> passive cooling. And it will return a variable-length Package containing a list
> of References to processor objects.
>
> Signed-off-by: Ivan Hu <ivan.hu@canonical.com>

Please check if this patch fixes the problem for you (it may need to
be rebased):

https://patchwork.kernel.org/project/linux-acpi/patch/20230330030446.2469338-1-vi@endrift.com/

> ---
>  include/acpi/acpi_bus.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
> index 23fbe4a16972..dc7b38826113 100644
> --- a/include/acpi/acpi_bus.h
> +++ b/include/acpi/acpi_bus.h
> @@ -13,7 +13,7 @@
>  #include <linux/property.h>
>
>  /* TBD: Make dynamic */
> -#define ACPI_MAX_HANDLES       10
> +#define ACPI_MAX_HANDLES       32
>  struct acpi_handle_list {
>         u32 count;
>         acpi_handle handles[ACPI_MAX_HANDLES];
> --
> 2.34.1
>