Re: [PATCH v2 2/4] staging: fbtft: Make FB_DEVICE dependency optional

[Chintan Patel]

Hi Andy,

On 12/27/25 06:19, Andy Shevchenko wrote:
> On Fri, Dec 19, 2025 at 7:43 AM Chintan Patel <chintanlike@xxxxxxxxx> wrote:
> > fbtft provides sysfs interfaces for debugging and gamma configuration,
> > but these are not required for the core driver.
> >
> > Drop the hard dependency on CONFIG_FB_DEVICE and make sysfs support
> > optional by using dev_of_fbinfo() at runtime. When FB_DEVICE is disabled,
> > sysfs operations are skipped while the code remains buildable and
> > type-checked.
>
> > v2:
> > - Replace CONFIG_FB_DEVICE ifdefs with runtime checks
> > - Use dev_of_fbinfo() to guard sysfs creation and removal
>
> The place for the change log is either a cover letter, or...
>
> > Suggested-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> > Suggested-by: Helge Deller <deller@xxxxxx>
> > Signed-off-by: Chintan Patel <chintanlike@xxxxxxxxx>
> > ---
>
> ...a comment block here. It's not so important to be in the Git
> history since we have a lore.kernel.org archive.

Thank you for suggestion! Will move to coverletter.

> >   drivers/staging/fbtft/Kconfig       |  5 ++++-
> >   drivers/staging/fbtft/fbtft-sysfs.c | 18 ++++++++++++++----
>
> ...
>
> >   void fbtft_sysfs_init(struct fbtft_par *par)
> >   {
> > -       device_create_file(par->info->dev, &debug_device_attr);
> > +       struct device *dev = dev_of_fbinfo(par->info);
> > +
> > +       if (!dev)
> > +               return;
>
>
> The better way is to decouple the definition and the assignment in the
> cases when it's followed by a conditional (validation check). In this
> case any new code added in between doesn't affect readability and
> maintenance efforts.
>
>         struct device *dev;
>
>         dev = dev_of_fbinfo(par->info);
>         if (!dev)
>                 return;
>
> > +       device_create_file(dev, &debug_device_attr);
> >          if (par->gamma.curves && par->fbtftops.set_gamma)
> > -               device_create_file(par->info->dev, &gamma_device_attrs[0]);
> > +               device_create_file(dev, &gamma_device_attrs[0]);
> >   }
>
> Ditto for the rest.

Will do v3 and re-send. Thanks for reviews!