Re: [PATCH 1/2] driver core: provide device_match_fwnode_ext()

[Dmitry Torokhov]

On Thu, Feb 19, 2026 at 03:15:53PM -0600, Bartosz Golaszewski wrote:
> On Thu, 19 Feb 2026 17:54:24 +0100, Dmitry Torokhov
> <dmitry.torokhov@xxxxxxxxx> said:
> > Hi Bartosz,
> >
> > On Thu, Feb 19, 2026 at 05:39:47PM +0100, Bartosz Golaszewski wrote:
> >> On Thu, Feb 19, 2026 at 5:36 PM Greg Kroah-Hartman
> >> <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> >> >
> >> > On Thu, Feb 19, 2026 at 05:31:22PM +0100, Bartosz Golaszewski wrote:
> >> > > Provide an extended variant of device_match_fwnode() that also tries to
> >> > > match the device's secondary fwnode.
> >> > >
> >> > > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxxxxxxxx>
> >> > > ---
> >> > >  drivers/base/core.c        | 14 ++++++++++++++
> >> > >  include/linux/device/bus.h |  1 +
> >> > >  2 files changed, 15 insertions(+)
> >> > >
> >> > > diff --git a/drivers/base/core.c b/drivers/base/core.c
> >> > > index f599a1384eec90c104601422b04dc2b4c19d4382..bbf1337978fafc35eb94bda85e0bb7f6879879c0 100644
> >> > > --- a/drivers/base/core.c
> >> > > +++ b/drivers/base/core.c
> >> > > @@ -5326,6 +5326,20 @@ int device_match_fwnode(struct device *dev, const void *fwnode)
> >> > >  }
> >> > >  EXPORT_SYMBOL_GPL(device_match_fwnode);
> >> > >
> >> > > +int device_match_fwnode_ext(struct device *dev, const void *fwnode)
> >> >
> >> > No kernel doc to explain what this function does?
> >> >
> >> > :(
> >> >
> >>
> >> It's not like any of the other variants from this file were documented
> >> but ok, I can add it in v2. Still, I'd like to hear if this even makes
> >> sense.
> >
> > I think it really needs a good explanation given how it goes through
> > secondaries on one side but not on the other (but maybe it should? Why
> > one would not want to match secondary?)
> >
> 
> I don't think it should. You have one, concrete fwnode and you want to match
> it against a struct device: in this variant both its primary and secondary
> nodes. I don't think we should do a four-way matching.

I wonder why you consider these 2 distinct fwnodes instead of a single
object that has multiple components? After all in device we have a
pointer to fwnode, and not list of fwnodes....

Thanks.

-- 
Dmitry