Re: [PATCH V6 09/11] ACPI: introduce flag .is_master_device

[Zhang Rui <rui.zhang@intel.com>]

On Thu, 2014-05-22 at 11:51 +0300, Mika Westerberg wrote:
> On Wed, May 21, 2014 at 10:43:07PM +0800, Zhang Rui wrote:
> > On 三, 2014-05-21 at 11:52 +0300, Mika Westerberg wrote:
> > > On Thu, May 15, 2014 at 02:44:14PM +0800, Zhang Rui wrote:
> > > > For some ACPI device objects, they represent master devices,
> > > > and their children devices are enumerated by bus controller drivers
> > > > for the buses they are on.
> > > > 
> > > > In this case, we do not want to enumerate their children devices to
> > > > platform bus explicitly in acpi scan code.
> > > > 
> > > > Thus a new flag .is_master_device is introduced in this patch.
> > > > 
> > > > For devices with this flag set, we will not do default enumeration
> > > > for their children.
> > > 
> > > Is there any particular reason we would like to enumerate everything
> > > below the first device by default?
> > 
> > we do not enumerate everything below the first device by default, we
> > just enumerate all the devices with _HID.
> 
> OK.
> 
> > But if a device has _HID and it is enumerated by its parents to a
> > separate bus, we need this flag set for its parent.
> 
> How about checking if the device has *SerialBus() connector and in such
> case skip the device (given that it is not listed in a special list,
> like acpi_platform_device_ids)?

This sounds like a good idea.
I think we can just ignore devices with ACPI_RESOURCE_TYPE_SERIAL_BUS
resources, and this can be done in drivers/acpi/scan.c for all _HID
devices w/o handler attached, right?

thanks,
rui