Re: [PATCH v5] wifi: cfg80211: move away from using a fake platform device

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Tue, Jul 01, 2025 at 01:06:46PM +0200, Johannes Berg wrote:
> On Tue, 2025-07-01 at 12:56 +0200, Greg Kroah-Hartman wrote:
> > Downloading regulatory "firmware" needs a device to hang off of, and so
> > a platform device seemed like the simplest way to do this.  Now that we
> > have a faux device interface, use that instead as this "regulatory
> > device" is not anything resembling a platform device at all.
> > 
> > Cc: Johannes Berg <johannes@sipsolutions.net>
> > Cc: <linux-wireless@vger.kernel.org>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > ---
> > v5: - rebase against 6.16-rc4 and actually cc: the relevant maintainers
> >       and mailing lists this time, doh!
> 
> I did wonder for a second why it's v5 and I never saw it ;-)
> 
> >  int __init regulatory_init(void)
> >  {
> > -	reg_pdev = platform_device_register_simple("regulatory", 0, NULL, 0);
> > -	if (IS_ERR(reg_pdev))
> > -		return PTR_ERR(reg_pdev);
> > +	reg_fdev = faux_device_create("regulatory", NULL, NULL);
> > +	if (!reg_fdev)
> > +		return -ENODEV;
> 
> Is that really -ENODEV rather than say -ENOMEM? Having a hard time
> imagining how a faux device creation would end up failing in any other
> case, there's no underlying device to bind to, after all? :)

There are some low-level functions that could fail, but the error that
I thought should be told to init would be "no device" as the device was
not created which is what really matters :)

> Anyway, that's not really all that relevant. I assume you want me to
> merge it through wireless-next, since we have faux.h in the tree now?

Please do, thanks!

greg k-h