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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2021-03-18 19:28:28 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2021-03-23 19:40:28 +0100 |
| commit | 7e4fdeafa61f2b653fcf9678f09935e55756aed2 (patch) | |
| tree | a281388cac429863a03305dba2c99cae11fb81a4 /drivers/acpi | |
| parent | ACPI: scan: Turn off unused power resources during initialization (diff) | |
| download | linux-7e4fdeafa61f2b653fcf9678f09935e55756aed2.tar.xz linux-7e4fdeafa61f2b653fcf9678f09935e55756aed2.zip | |
ACPI: power: Turn off unused power resources unconditionally
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/20210314000439.3138941-1-luzmaximilian@gmail.com/ # [2]
Tested-by: Wendy Wang <wendy.wang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/power.c | 11 |
1 files changed, 1 insertions, 10 deletions
diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c index 46c38627addd..bacae6d178ff 100644 --- a/drivers/acpi/power.c +++ b/drivers/acpi/power.c @@ -1005,18 +1005,9 @@ void acpi_turn_off_unused_power_resources(void) 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); } |