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);
}