On Mon, 2014-04-28 at 00:26 +0200, Rafael J. Wysocki wrote:
> On Tuesday, April 08, 2014 12:06:59 AM Zhang Rui wrote:
> > For some devices with scan handler attached, their children devices
> > are enumerated by the scan handler, indirectly.
>
> This isn't the case really. They are enumerated by bus controller drivers
> for the buses they are on.
>
that's what I mean by saying "indirectly". :)
> > In this case, we do not want to enumerate the children devices in
> > acpi scan code explicitly.
> >
> > Thus a new flag .handle_children is introduced in this patch.
> >
> > For scan handlers with this flag set, we will do default enumeration neither
> > for the attached devices nor for the children of the attached devices.
>
> I'm not sure if that is the right approach. I would prefer that to be
> handled in a more fine-graind manner, like a flag per device ID or something
> similar?
>
hmmm, how about this,
first, keep the device->flags.no_child_enumeration flag introduced in
this patch
second, set the flag explicitly, for specified devices, in the scan
handler .attach() function.
thanks,
rui
> > Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
> > ---
> > drivers/acpi/acpi_lpss.c | 2 ++
> > drivers/acpi/scan.c | 28 ++++++++++++++++++++++++++--
> > include/acpi/acpi_bus.h | 4 +++-
> > 3 files changed, 31 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
> > index 965428f..da0a3d4 100644
> > --- a/drivers/acpi/acpi_lpss.c
> > +++ b/drivers/acpi/acpi_lpss.c
> > @@ -521,6 +521,7 @@ static struct acpi_scan_handler lpss_handler = {
> > .attach = acpi_lpss_create_device,
> > .bind = acpi_lpss_bind,
> > .unbind = acpi_lpss_unbind,
> > + .handle_children = true,
> > };
> >
> > #endif /* CONFIG_X86_INTEL_LPSS */
> > @@ -534,6 +535,7 @@ static int acpi_lpss_dummy_attach(struct acpi_device *adev,
> > static struct acpi_scan_handler lpss_dummy_handler = {
> > .ids = acpi_lpss_device_ids,
> > .attach = acpi_lpss_dummy_attach,
> > + .handle_children = true,
> > };
> >
> > void __init acpi_lpss_init(void)
> > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> > index 44c4668..4ea867e 100644
> > --- a/drivers/acpi/scan.c
> > +++ b/drivers/acpi/scan.c
> > @@ -2073,6 +2073,31 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl_not_used,
> > return AE_OK;
> > }
> >
> > +static void acpi_do_default_enumeration(struct acpi_device *device)
> > +{
> > + /*
> > + * Do not do enumeration for device object that
> > + * its parent doesn't want to
> > + */
> > + if (device->parent && device->parent->flags.no_child_enumeration) {
> > + device->flags.no_child_enumeration = 1;
> > + return;
> > + }
> > +
> > + /* Do not do enumeration for device object with scan handler attached */
> > + if (device->handler) {
> > + if (device->handler->handle_children)
> > + device->flags.no_child_enumeration = 1;
> > + return;
> > + }
> > +
> > + /* Do not do enumeration for device object w/o platform_id */
> > + if (!device->pnp.type.platform_id)
> > + return;
> > +
> > + acpi_create_platform_device(device, NULL);
> > +}
> > +
> > static int acpi_scan_attach_handler(struct acpi_device *device)
> > {
> > struct acpi_hardware_id *hwid;
> > @@ -2095,8 +2120,7 @@ static int acpi_scan_attach_handler(struct acpi_device *device)
> > }
> > }
> >
> > - if (device->pnp.type.platform_id && !device->handler)
> > - acpi_create_platform_device(device, NULL);
> > + acpi_do_default_enumeration(device);
> >
> > return ret;
> > }
> > diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
> > index ec92ad3..4724fe5 100644
> > --- a/include/acpi/acpi_bus.h
> > +++ b/include/acpi/acpi_bus.h
> > @@ -137,6 +137,7 @@ struct acpi_scan_handler {
> > void (*bind)(struct device *phys_dev);
> > void (*unbind)(struct device *phys_dev);
> > struct acpi_hotplug_profile hotplug;
> > + bool handle_children;
> > };
> >
> > /*
> > @@ -207,7 +208,8 @@ struct acpi_device_flags {
> > u32 no_hotplug:1;
> > u32 hotplug_notify:1;
> > u32 is_dock_station:1;
> > - u32 reserved:22;
> > + u32 no_child_enumeration:1;
> > + u32 reserved:21;
> > };
> >
> > /* File System */
> >
>
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