On Thu, May 21, 2009 at 05:28:53PM -0600, Bjorn Helgaas wrote: > 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> Acked-by: Matthew Garrett <mjg@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; > > > -- Matthew Garrett | mjg59@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
