RE: [PATCH v7 0/4] Extend device_get_match_data() to struct bus_type

Biju Das
2023-08-15T07:12:42Z

> Subject: RE: [PATCH v7 0/4] Extend device_get_match_data() to struct
> bus_type
>
>
> Hi Andy Shevchenko,
>
> Thanks for the feedback.
>
> > Subject: Re: [PATCH v7 0/4] Extend device_get_match_data() to struct
> > bus_type
> >
> > On Fri, Aug 11, 2023 at 02:46:10PM +0000, Biju Das wrote:
> > > > Subject: Re: [PATCH v7 0/4] Extend device_get_match_data() to
> > > > struct bus_type On Fri, Aug 11, 2023 at 01:27:36PM +0000, Biju Das
> wrote:
> > > > > > On Thu, Aug 10, 2023 at 09:05:10AM +0000, Biju Das wrote:
> >
> > ...
> >
> > > > > > I'm good with this approach, but make sure you checked the
> > > > > > whole kernel source tree for a such.
> > > > >
> > > > > Checking against 16 is too short I guess??
> > > > >
> > > > > drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h has 18 enums.
> > > >
> > > > So, what does prevent us from moving that tables to use pointers?
> > >
> > > I think that will lead to ABI breakage(client->name vs id->name)
> > >
> > > match = device_get_match_data(&client->dev);
> > > if (match) {
> > > chip_type = (uintptr_t)match;
> > > name = client->name;
> > > } else if (id) {
> > > chip_type = (enum inv_devices)
> > > id->driver_data;
> > > name = id->name;
> > > } else {
> > > return -ENOSYS;
> > > }
> >
> >
> > It's easy to work around (may be better fix can be found, haven't
> > checked, just what first comes to my mind):
> >
> > match ...
> > name = match->name;
>
> The device_get_match_data()API returns matched data, so we cannot use that
> one here.
>
> Maybe??
>
> /* If enumerated via ID lookup, fix the ABI */ if (!dev_fwnode())
> name = id->name;

Looks this will work.

/* If enumerated via firmware node, fix the ABI */
if (dev_fwnode())
name = client->name
else
name = id->name

Cheers,
Biju