Re: introduce device_is_attached()

[Christoph Egger <Christoph_Egger%gmx.de@localhost>]

On 04/16/12 19:41, Christoph Egger wrote:
> On 16.04.12 19:12, Matt Thomas wrote:
> > On Apr 16, 2012, at 9:52 AM, Christoph Egger wrote:
> >
> > > Hi,
> > >
> > > I want to introduce a new function to sys/devices.h:
> > >
> > > bool device_is_attached(device_t parent, cfdata_t cf);
> >
> > I'd prefer device_is_attached_p
>
> Ok, I will rename it.
>
> > > The purpose is for bus drivers who wants to attach children
> > > and ensure that only one instance of it will attach.
> > >
> > > 'parent' is the bus driver and 'cf' is the child device
> > > as passed to the submatch callback via config_search_loc().
> > >
> > > The return value is true if the child is already attached.
> >
> > Can it be used in driver match routines so they don't need to
> > keep a local to prevent multiple matches?
>
> Oh, good point. I think this is possible and will make
> struct amdnb_misc_softc completely superflous.
> I will give this a try tomorrow.

Ok, I can confirm it is also usable in the child driver match routines.
However, the local is still needed for the rescan hook.

Christoph