Re: [PATCH v4 3/7] pinctrl: extract pinctrl_generic_to_map() from pinctrl_generic_pins_function_dt_node_to_map()

[Conor Dooley]

On Fri, Mar 27, 2026 at 12:54:42PM -0400, Frank Li wrote:
> On Fri, Mar 27, 2026 at 12:09:32AM +0000, Conor Dooley wrote:
> > On Wed, Mar 25, 2026 at 07:04:12PM -0400, Frank Li wrote:
> > > Refactor pinctrl_generic_pins_function_dt_subnode_to_map() by separating DT
> > > parsing logic from map creation. Introduce a new helper
> > > pinctrl_generic_to_map() to handle mapping to kernel data structures, while
> > > keeping DT property parsing in the subnode function.
> > >
> > > Improve code structure and enables easier reuse for platforms using
> > > different DT properties (e.g. pinmux) without modifying the
> > > dt_node_to_map-style callback API. Avoid unnecessary coupling to
> > > pinctrl_generic_pins_function_dt_node_to_map(), which provides
> > > functionality not needed when the phandle target is unambiguous.
> > >
> > > Maximize code reuse and provide a cleaner extension point for future
> > > pinctrl drivers.
> > >
> > > Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
> > > ---
> > > change in v4
> > > - new patch
> > > ---
> > >  drivers/pinctrl/pinconf.h         | 18 ++++++++
> > >  drivers/pinctrl/pinctrl-generic.c | 91 ++++++++++++++++++++++++---------------
> > >  2 files changed, 74 insertions(+), 35 deletions(-)
> > >
> > > diff --git a/drivers/pinctrl/pinconf.h b/drivers/pinctrl/pinconf.h
> > > index 2880adef476e68950ffdd540ea42cdee6a16ec27..ffdabddb9660324ed8886a2e8dcacff7e1c6c529 100644
> > > --- a/drivers/pinctrl/pinconf.h
> > > +++ b/drivers/pinctrl/pinconf.h
> > > @@ -166,6 +166,13 @@ int pinctrl_generic_pins_function_dt_node_to_map(struct pinctrl_dev *pctldev,
> > >  						 struct device_node *np,
> > >  						 struct pinctrl_map **maps,
> > >  						 unsigned int *num_maps);
> > > +
> > > +int
> > > +pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,
> > > +		       struct device_node *np, struct pinctrl_map **maps,
> > > +		       unsigned int *num_maps, unsigned int *num_reserved_maps,
> > > +		       const char **group_name, unsigned int ngroups,
> > > +		       const char **functions, unsigned int *pins);
> > >  #else
> > >  static inline int
> > >  pinctrl_generic_pins_function_dt_node_to_map(struct pinctrl_dev *pctldev,
> > > @@ -175,4 +182,15 @@ pinctrl_generic_pins_function_dt_node_to_map(struct pinctrl_dev *pctldev,
> > >  {
> > >  	return -ENOTSUPP;
> > >  }
> > > +
> > > +static inline int
> > > +pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,
> > > +		       struct device_node *np, struct pinctrl_map **maps,
> > > +		       unsigned int *num_maps, unsigned int *num_reserved_maps,
> > > +		       const char **group_name, unsigned int ngroups,
> > > +		       const char **functions, unsigned int *pins,
> > > +		       void *function_data)
> > > +{
> > > +	return -ENOTSUPP;
> > > +}
> > >  #endif
> > > diff --git a/drivers/pinctrl/pinctrl-generic.c b/drivers/pinctrl/pinctrl-generic.c
> > > index efb39c6a670331775855efdc8566102b5c6202ef..20a216ae63e91b69985ea4cfcd0b57103c6ca950 100644
> > > --- a/drivers/pinctrl/pinctrl-generic.c
> > > +++ b/drivers/pinctrl/pinctrl-generic.c
> > > @@ -17,29 +17,18 @@
> > >  #include "pinctrl-utils.h"
> > >  #include "pinmux.h"
> > >
> > > -static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *pctldev,
> > > -							   struct device_node *parent,
> > > -							   struct device_node *np,
> > > -							   struct pinctrl_map **maps,
> > > -							   unsigned int *num_maps,
> > > -							   unsigned int *num_reserved_maps,
> > > -							   const char **group_names,
> > > -							   unsigned int ngroups)
> > > +int
> > > +pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,
> > > +		       struct device_node *np, struct pinctrl_map **maps,
> > > +		       unsigned int *num_maps, unsigned int *num_reserved_maps,
> > > +		       const char **group_names, unsigned int ngroups,
> > > +		       const char **functions, unsigned int *pins)
> >
> > npins needs to be an argument to this function also, otherwise
> > pinctrl_generic_add_group() uses it uninitialised...
> 
> Is this one the root cause of then broken?

No, this is not the cause of the breakage. I can't believe I still have
to say that. Go read the code and you'll see why that allocation thing
is problematic.

> I am not sure why compiler have not report waring for it.

It did, that's how I found it. Used uninitialised warnings are normally
from clang, so your toolchain might not have seen it. clangd integration
with my editor is how I saw it.

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