Hi Dmitry Torokhov,
Thanks for the feedback.
> Subject: Re: [PATCH v3 2/2] i2c: Add i2c_device_get_match_data()
> callback
>
> On Tue, Aug 01, 2023 at 10:28:38PM +0300, Andy Shevchenko wrote:
> > On Tue, Aug 01, 2023 at 06:03:18PM +0100, Biju Das wrote:
> > > Add i2c_device_get_match_data() callback to struct bus_type().
> > >
> > > While at it, introduced i2c_get_match_data_helper() to avoid code
> > > duplication with i2c_get_match_data().
> >
> > Have you used --patience when prepared the patch for sending?
> >
> > ...
> >
> > > -const void *i2c_get_match_data(const struct i2c_client *client)
> > > +static const void *i2c_get_match_data_helper(const struct
> i2c_driver *driver,
> > > + const struct i2c_client *client)
> > > {
> >
> > > - struct i2c_driver *driver = to_i2c_driver(client->dev.driver);
> >
> > Does it make sense to remove and add an additional parameter? In one
> > case it's a copy, in another it probably the same, just hidden in the
> code.
> >
> > > const struct i2c_device_id *match;
> > > +
> > > + match = i2c_match_id(driver->id_table, client);
> > > + if (!match)
> > > + return NULL;
> > > +
> > > + return (const void *)match->driver_data; }
> > > +
> > > +static const void *i2c_device_get_match_data(const struct device
> > > +*dev) {
> > > + /* TODO: use i2c_verify_client() when it accepts const pointer */
> > > + const struct i2c_client *client = (dev->type ==
> &i2c_client_type) ?
> > > + to_i2c_client(dev) : NULL;
> > > const void *data;
> >
> > > + if (!dev->driver)
> > > + return NULL;
> >
> > When can this be true?
>
> It is not guaranteed that the function is always called on a device
> bound to a driver (even though we normally expect this to be the case).
>
> >
> > > + data = i2c_get_match_data_helper(to_i2c_driver(dev->driver),
> client);
> > > + if (data)
> > > + return data;
> > >
> > > - data = (const void *)match->driver_data;
> > > + if (dev->driver->of_match_table) {
> > > + const struct of_device_id *match;
> > > +
> > > + match = i2c_of_match_device_sysfs(dev->driver-
> >of_match_table,
> > > + (struct i2c_client *)client);
>
> Can we make i2c_of_match_device_sysfs() take a const pointer to a
> client? Casting away constness is something that we should avoid.
I agree, we are not supposed to modify client pointer inside
i2c_of_match_device_sysfs(), so const makes sense here.
Wolfram, I guess you are ok with it.
>
> > > + if (match)
> > > + data = match->data;
> > > }
> > >
> > > return data;
> > > }
> >
> > ...
> >
> > > -static const struct of_device_id*
> > > +const struct of_device_id*
> >
> > While here, add a missing space after of_device_id.
> >
> > ...
> >
> > > +const struct of_device_id*
> >
> > Ditto.
> >
> > Or use below (weird) style in case it occurs more often than usual
> one.
> >
> > > +i2c_of_match_device_sysfs(const struct of_device_id *matches,
> > > + struct i2c_client *client);
> > > +
> > > const struct of_device_id
> > > *i2c_of_match_device(const struct of_device_id *matches,
> > > struct i2c_client *client);
> >
> > ...
> >
> > > +static inline const struct of_device_id *i2c_of_match_device(const
> > > +struct of_device_id *matches,
> >
> > As per above.
>
> Was it supposed to be i2c_of_match_device_sysfs()? Also, this should be
> in drivers/i2c/i2c-core.h, not in public header.
Agreed.
Cheers,
Biju
