Re: [PATCH 1/2] ACPI: reintroduce acpi_device_ops .shutdown method

From: Bjorn Helgaas
Date: Tue Jun 30 2009 - 19:12:16 EST


On Tuesday 30 June 2009 3:10:47 pm Andrew Morton wrote:
> On Sat, 27 Jun 2009 07:18:31 +0200
> David H__rdeman <david@xxxxxxxxxxx> wrote:
>
> > This reintroduces the .shutdown method which is used by the
> > winbond-cir driver. A normal revert wasn't possible since there
> > had been other changes to include/acpi/acpi_bus.h since.
> >
> > Signed-off-by: David H__rdeman <david@xxxxxxxxxxx>
> > ---
> > drivers/acpi/scan.c | 12 ++++++++++++
> > include/acpi/acpi_bus.h | 2 ++
> > 2 files changed, 14 insertions(+), 0 deletions(-)
> >
> > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> > index 781435d..c94ab13 100644
> > --- a/drivers/acpi/scan.c
> > +++ b/drivers/acpi/scan.c
> > @@ -464,10 +464,22 @@ static int acpi_device_remove(struct device * dev)
> > return 0;
> > }
> >
> > +static void acpi_device_shutdown(struct device *dev)
> > +{
> > + struct acpi_device *acpi_dev = to_acpi_device(dev);
> > + struct acpi_driver *acpi_drv = acpi_dev->driver;
> > +
> > + if (acpi_drv && acpi_drv->ops.shutdown)
> > + acpi_drv->ops.shutdown(acpi_dev);
> > +
> > + return ;
> > +}
> > +
> > struct bus_type acpi_bus_type = {
> > .name = "acpi",
> > .suspend = acpi_device_suspend,
> > .resume = acpi_device_resume,
> > + .shutdown = acpi_device_shutdown,
> > .match = acpi_bus_match,
> > .probe = acpi_device_probe,
> > .remove = acpi_device_remove,
> > diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
> > index c65e4ce..52da89a 100644
> > --- a/include/acpi/acpi_bus.h
> > +++ b/include/acpi/acpi_bus.h
> > @@ -96,6 +96,7 @@ typedef int (*acpi_op_resume) (struct acpi_device * device);
> > typedef int (*acpi_op_bind) (struct acpi_device * device);
> > typedef int (*acpi_op_unbind) (struct acpi_device * device);
> > typedef void (*acpi_op_notify) (struct acpi_device * device, u32 event);
> > +typedef int (*acpi_op_shutdown) (struct acpi_device * device);
> >
> > struct acpi_bus_ops {
> > u32 acpi_op_add:1;
> > @@ -112,6 +113,7 @@ struct acpi_device_ops {
> > acpi_op_bind bind;
> > acpi_op_unbind unbind;
> > acpi_op_notify notify;
> > + acpi_op_shutdown shutdown;
> > };
> >
> > #define ACPI_DRIVER_ALL_NOTIFY_EVENTS 0x1 /* system AND device events */
>
> Len, Bjorn: is this OK? Or is there some other mechanism which the
> driver should have used?

I'm on vacation and don't have time to read the new winbond driver
right now, but maybe it could be changed so that wbcir_shutdown()
is an internal function called by wbcir_suspend() (as it is already)
and wbcir_remove().

I hate to re-introduce .shutdown when it's only used by a single
driver. That makes me think either we have a bunch of drivers that
are buggy because they *should* have .shutdown methods but don't,
or the single user of .shutdown doesn't have a real dependency on it.

The winbond driver does not use any ACPI-specific functionality, so
it might be simpler to write it as a PNP driver (which would depend
on PNPACPI, of course).

Nice looking driver, by the way. Even from a cursory glance it's
obvious that you've taken a lot of care with it.

Bjorn
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