We used to evaluate _STA to check the power state of a device after
running _ON or _OFF. But as far as I can tell, there's no benefit
to evaluating _STA, and sometimes we trip over bugs when BIOSes don't
implement _STA correctly.
Yakui says Windows XP doesn't evaluate _STA during power transition.
So let's skip it in Linux, too. It's conceivable that we'll need to
check _STA in the future for some reason, but until we do, I don't
see a reason to clutter this code path.
References:
http://bugzilla.kernel.org/show_bug.cgi?id=13243
http://marc.info/?l=linux-acpi&m=124166053803753&w=2
http://marc.info/?l=linux-acpi&m=124175761408256&w=2
http://marc.info/?l=linux-acpi&m=124210593114061&w=2
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@xxxxxx>
CC: Yakui Zhao <yakui.zhao@xxxxxxxxx>
CC: Matthew Garrett <mjg59@xxxxxxxxxxxxx>
CC: "Rafael J. Wysocki" <rjw@xxxxxxx>
CC: Witold Szczeponik <Witold.Szczeponik@xxxxxxx>
CC: Alexey Starikovskiy <astarikovskiy@xxxxxxx>
CC: Len Brown <lenb@xxxxxxxxxx>
---
drivers/acpi/power.c | 28 ++--------------------------
1 files changed, 2 insertions(+), 26 deletions(-)
diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 56665a6..d74365d 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -194,7 +194,7 @@ static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
{
- int result = 0, state;
+ int result = 0;
int found = 0;
acpi_status status = AE_OK;
struct acpi_power_resource *resource = NULL;
@@ -236,18 +236,6 @@ static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
if (ACPI_FAILURE(status))
return -ENODEV;
- if (!acpi_power_nocheck) {
- /*
- * If acpi_power_nocheck is set, it is unnecessary to check
- * the power state after power transition.
- */
- result = acpi_power_get_state(resource->device->handle,
- &state);
- if (result)
- return result;
- if (state != ACPI_POWER_RESOURCE_STATE_ON)
- return -ENOEXEC;
- }
/* Update the power resource's _device_ power state */
resource->device->power.state = ACPI_STATE_D0;
@@ -258,7 +246,7 @@ static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
{
- int result = 0, state;
+ int result = 0;
acpi_status status = AE_OK;
struct acpi_power_resource *resource = NULL;
struct list_head *node, *next;
@@ -293,18 +281,6 @@ static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
if (ACPI_FAILURE(status))
return -ENODEV;
- if (!acpi_power_nocheck) {
- /*
- * If acpi_power_nocheck is set, it is unnecessary to check
- * the power state after power transition.
- */
- result = acpi_power_get_state(handle, &state);
- if (result)
- return result;
- if (state != ACPI_POWER_RESOURCE_STATE_OFF)
- return -ENOEXEC;
- }
-
/* Update the power resource's _device_ power state */
resource->device->power.state = ACPI_STATE_D3;
--
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