From bdf43bbf2e19952d82995a50e00cb4b66afa4f0c Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Thu, 21 May 2009 17:28:53 -0600 Subject: [PATCH] ACPI: don't check power state after _ON/_OFF 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 Acked-by: Matthew Garrett Signed-off-by: Len Brown --- drivers/acpi/power.c | 28 ++-------------------------- 1 file changed, 2 insertions(+), 26 deletions(-) diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c index 56665a63bf19..d74365d4a6e7 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;