Re: [PATCH v1 3/3] mmc: Add driver for LiteX's LiteSDCard interface

Geert Uytterhoeven
2021-12-07T08:01:57Z

Hi Joel,

On Tue, Dec 7, 2021 at 12:51 AM Joel Stanley <joel@jms.id.au> wrote:
> On Mon, 6 Dec 2021 at 12:16, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> > > > + depends on OF && LITEX
> > >
> > > I don't like having litex drivers depend on the LITEX kconfig. The
> > > symbol is not user visible, and to enable it we need to build in the
> > > litex controller driver, which platforms may or may not have.
> > >
> > > The microwatt platform is an example of a SoC that embeds some LITEX
> > > IP, but may or may not be a litex SoC.
> >
> > I do like the LITEX dependency, as it allows us to gate off a bunch of
> > related drivers, and avoid annoying users with questions about them,
> > using a single symbol.
>
> I appreciate your concern.
>
> We could do this:
>
> depends on PPC_MICROWATT || LITEX || COMPILE_TEST
>
> It's unfortunate that kconfig doesn't let us describe the difference
> between "this driver requires this symbol" as it won't build and "this
> driver is only useful when this symbol is enabled". Traditionally I
> write kconfig to represent only the former, whereas you prefer both.

The former is expressed using:

depends on FOO

The latter using:

depends on BAR || COMPILE_TEST

Traditionally we only had the former. But with the introduction of
more and more dummy symbols for the !CONFIG_BAR case, the amount of
questions asked during configuration has become overwhelming. At the
current pace, we'll reach 20K config symbols by v5.24 or so...

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds