[PATCH v1 09/35] drm/modes: Move named modes parsing to a separate function

[Geert Uytterhoeven]

Hi Maxime,

On Tue, Aug 16, 2022 at 3:46 PM Maxime Ripard <maxime at cerno.tech> wrote:
> On Fri, Aug 12, 2022 at 03:27:17PM +0200, Geert Uytterhoeven wrote:
> > On Fri, Jul 29, 2022 at 6:36 PM Maxime Ripard <maxime at cerno.tech> wrote:
> > > The current construction of the named mode parsing doesn't allow to extend
> > > it easily. Let's move it to a separate function so we can add more
> > > parameters and modes.
> > >
> > > Signed-off-by: Maxime Ripard <maxime at cerno.tech>
> >
> > Thanks for your patch, which looks similar to my "[PATCH v2 2/5]
> > drm/modes: Extract drm_mode_parse_cmdline_named_mode()"
> > (https://lore.kernel.org/dri-devel/1371554419ae63cb54c2a377db0c1016fcf200bb.1657788997.git.geert@linux-m68k.org
> > ;-)
>
> Indeed, I forgot about that one, sorry :/
>
> I think I'd still prefer to have the check for refresh + named mode
> outside of the function, since I see them as an "integration" issue, not
> a parsing one.
>
> It's not the named mode parsing that fails, but the fact that we both
> have a valid refresh and a valid named mode.
>
> >
> > > --- a/drivers/gpu/drm/drm_modes.c
> > > +++ b/drivers/gpu/drm/drm_modes.c
> > > @@ -1773,6 +1773,28 @@ static const char * const drm_named_modes_whitelist[] = {
> > >         "PAL",
> > >  };
> > >
> > > +static bool drm_mode_parse_cmdline_named_mode(const char *name,
> > > +                                             unsigned int name_end,
> > > +                                             struct drm_cmdline_mode *cmdline_mode)
> > > +{
> > > +       unsigned int i;
> > > +
> > > +       for (i = 0; i < ARRAY_SIZE(drm_named_modes_whitelist); i++) {
> > > +               int ret;
> > > +
> > > +               ret = str_has_prefix(name, drm_named_modes_whitelist[i]);
> > > +               if (ret != name_end)
> > > +                       continue;
> > > +
> > > +               strcpy(cmdline_mode->name, drm_named_modes_whitelist[i]);
> > > +               cmdline_mode->specified = true;
> > > +
> > > +               return true;
> > > +       }
> > > +
> > > +       return false;
> >
> > What's the point in returning a value, if it is never checked?
> > Just make this function return void?
>
> Yeah, it's something I went back and forth to between the dev, and it's
> an artifact.
>
> I'll drop that patch, take your version and move the refresh check to
> drm_mode_parse_command_line_for_connector if that's alright for you?

Fine for me.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at 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