On Monday, January 14, 2013 04:13:43 PM Toshi Kani wrote:
> On Mon, 2013-01-14 at 22:39 +0100, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> >
> > Make acpi_bus_trim() work in analogy with acpi_bus_scan() and carry
> > out two passes such that ACPI drivers will be detached from device
> > nodes being removed in the first pass and the device nodes themselves
> > will be removed in the second pass.
> >
> > For this purpose split the driver unregistration out of
> > acpi_bus_remove() into a new routine, acpi_bus_device_detach(), that
> > will be executed by acpi_bus_trim() in the additional first pass as
> > a post-order callback.
> >
> > This is necessary, because some ACPI drivers' .remove() routines
> > unregister struct device objects associated with the ACPI device
> > nodes being removed and that needs to happen while the ACPI
> > device nodes are still around (for example, in case they need to be
> > used for power management or similar things at that time).
> >
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
> I'd suggest to add some comment stating that acpi_bus_device_detach()
> acpi_bus_remove() are post-order callbacks. I do not think many people
> recognize it by just looking the calls to acpi_walk_namespace().
Yeah, good idea.
> Otherwise, the patchset looks good. For the patch series:
> Acked-by: Toshi Kani <toshi.kani@xxxxxx>
Thanks!
Rafael
> > ---
> > drivers/acpi/scan.c | 44 ++++++++++++++++++++++++++++----------------
> > 1 file changed, 28 insertions(+), 16 deletions(-)
> >
> > Index: linux-pm/drivers/acpi/scan.c
> > ===================================================================
> > --- linux-pm.orig/drivers/acpi/scan.c
> > +++ linux-pm/drivers/acpi/scan.c
> > @@ -1425,22 +1425,6 @@ static void acpi_device_set_id(struct ac
> > }
> > }
> >
> > -static acpi_status acpi_bus_remove(acpi_handle handle, u32 lvl_not_used,
> > - void *not_used, void **ret_not_used)
> > -{
> > - struct acpi_device *dev = NULL;
> > -
> > - if (acpi_bus_get_device(handle, &dev))
> > - return AE_OK;
> > -
> > - dev->removal_type = ACPI_BUS_REMOVAL_EJECT;
> > - device_release_driver(&dev->dev);
> > -
> > - acpi_device_unregister(dev);
> > -
> > - return AE_OK;
> > -}
> > -
> > void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
> > int type, unsigned long long sta)
> > {
> > @@ -1647,8 +1631,36 @@ int acpi_bus_add(acpi_handle handle)
> > }
> > EXPORT_SYMBOL(acpi_bus_add);
> >
> > +static acpi_status acpi_bus_device_detach(acpi_handle handle, u32 lvl_not_used,
> > + void *not_used, void **ret_not_used)
> > +{
> > + struct acpi_device *device = NULL;
> > +
> > + if (!acpi_bus_get_device(handle, &device)) {
> > + device->removal_type = ACPI_BUS_REMOVAL_EJECT;
> > + device_release_driver(&device->dev);
> > + }
> > + return AE_OK;
> > +}
> > +
> > +static acpi_status acpi_bus_remove(acpi_handle handle, u32 lvl_not_used,
> > + void *not_used, void **ret_not_used)
> > +{
> > + struct acpi_device *device = NULL;
> > +
> > + if (!acpi_bus_get_device(handle, &device))
> > + acpi_device_unregister(device);
> > +
> > + return AE_OK;
> > +}
> > +
> > int acpi_bus_trim(struct acpi_device *start)
> > {
> > + /* Detach all ACPI drivers from the device nodes being removed. */
> > + acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL,
> > + acpi_bus_device_detach, NULL, NULL);
> > + acpi_bus_device_detach(start->handle, 0, NULL, NULL);
> > + /* Remove the device nodes. */
> > acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL,
> > acpi_bus_remove, NULL, NULL);
> > acpi_bus_remove(start->handle, 0, NULL, NULL);
> >
>
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
--
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
