From: Rafael J. Wysocki <[email protected]> According to the ACPI specification (section 7.2.2 in ACPI 6.4), the OS may evaluate the _OFF method of a power resource that is "off" already [1], and in particular that can be done in the case of unused power resources.
Accordingly, modify acpi_turn_off_unused_power_resources() to evaluate the _OFF method for each of the unused power resources unconditionally which may help to work around BIOS issues where the return value of _STA for a power resource does not reflect the actual state of the power resource [2]. Link: https://uefi.org/specs/ACPI/6.4/07_Power_and_Performance_Mgmt/declaring-a-power-resource-object.html#off # [1] Link: https://lore.kernel.org/lkml/[email protected]/ # [2] Signed-off-by: Rafael J. Wysocki <[email protected]> --- New patch in v2. --- drivers/acpi/power.c | 11 +---------- 1 file changed, 1 insertion(+), 10 deletions(-) Index: linux-pm/drivers/acpi/power.c =================================================================== --- linux-pm.orig/drivers/acpi/power.c +++ linux-pm/drivers/acpi/power.c @@ -1005,18 +1005,9 @@ void acpi_turn_off_unused_power_resource mutex_lock(&power_resource_list_lock); list_for_each_entry_reverse(resource, &acpi_power_resource_list, list_node) { - int result, state; - mutex_lock(&resource->resource_lock); - result = acpi_power_get_state(resource->device.handle, &state); - if (result) { - mutex_unlock(&resource->resource_lock); - continue; - } - - if (state == ACPI_POWER_RESOURCE_STATE_ON - && !resource->ref_count) { + if (!resource->ref_count) { dev_info(&resource->device.dev, "Turning OFF\n"); __acpi_power_off(resource); }
