Re: [PATCH v2] gpio: swnode: restore the swnode-name-against-chip-label matching

[Bartosz Golaszewski]

On Wed, Feb 18, 2026 at 6:15 PM Dmitry Torokhov
<dmitry.torokhov@xxxxxxxxx> wrote:
>
> On Wed, Feb 18, 2026 at 09:42:28AM +0100, Bartosz Golaszewski wrote:
> > On Wed, Feb 18, 2026 at 1:31 AM Dmitry Torokhov
> > <dmitry.torokhov@xxxxxxxxx> wrote:
> > >
> > > On Wed, Feb 11, 2026 at 09:53:13AM +0100, Bartosz Golaszewski wrote:
> > > > Using the remote firmware node for software node lookup is the right
> > > > thing to do. The GPIO controller we want to resolve should have the
> > > > software node we scooped out of the reference attached to it. However,
> > > > there are existing users who abuse the software node API by creating
> > > > dummy swnodes whose name is set to the expected label string of the GPIO
> > > > controller whose pins they want to control and use them in their local
> > > > swnode references as GPIO properties.
> > > >
> > > > This used to work when we compared the software node's name to the
> > > > chip's label. When we switched to using a real fwnode lookup, these
> > > > users broke down because the firmware nodes in question were never
> > > > attached to the controllers they were looking for.
> > > >
> > > > Restore the label matching as a fallback to fix the broken users but add
> > > > a big FIXME urging for a better solution.
> > > >
> > > > Cc: stable@xxxxxxxxxxxxxxx # v6.18, v6.19
> > > > Fixes: 216c12047571 ("gpio: swnode: allow referencing GPIO chips by firmware nodes")
> > > > Link: https://lore.kernel.org/all/aYkdKfP5fg6iywgr@jekhomev/
> > > > Acked-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> > > > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxxxxxxxx>
> > > > ---
> > > > Changes in v2:
> > > > - check if gdev_node and gdev_node->name are not NULL before trying to
> > > >   match the label (Hans & Dan)
> > > > - use the right link
> > > > - collect tags
> > > >
> > > >  drivers/gpio/gpiolib-swnode.c | 19 +++++++++++++++++++
> > > >  1 file changed, 19 insertions(+)
> > > >
> > > > diff --git a/drivers/gpio/gpiolib-swnode.c b/drivers/gpio/gpiolib-swnode.c
> > > > index 21478b45c127d..0d7f3f09a0b4b 100644
> > > > --- a/drivers/gpio/gpiolib-swnode.c
> > > > +++ b/drivers/gpio/gpiolib-swnode.c
> > > > @@ -42,6 +42,25 @@ static struct gpio_device *swnode_get_gpio_device(struct fwnode_handle *fwnode)
> > > >
> > > >  fwnode_lookup:
> > > >       gdev = gpio_device_find_by_fwnode(fwnode);
> > >
> > > By the way, should we extend gpio_device_find_by_fwnode() to use both
> > > primary and secondary nodes?
> > >
> >
> > That's already done on a higher lever for all fwnodes in gpiod_fwnode_lookup().
>
> How exactly? I am not talking about checking secondary node for the
> fwnode that is used in the reference, I am talking about secondary
> fwnode that might be assigned to the gpio chip and you need to check
> both primary and secondary if they match with the fwnode that you call
> gpio_device_find_by_fwnode() with.
>

Right, I didn't quite get it. I was surprised to find out
device_match_fwnode() - which we use in gpiolib - does not do it
already. I'm wondering if this is something we should change in device
core or only locally.

Bartosz