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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Tue, 16 Aug 2022 16:43:44 +0200
Message-ID: <CAMuHMdXq_xGPx46bdnUFGDiG4kcgdxtXaRGTucFd3TRq8353dg@mail.gmail.com>
Subject: Re: [PATCH v1 05/35] drm/connector: Add TV standard property
To:     Maxime Ripard <maxime@cerno.tech>
Cc:     Jernej Skrabec <jernej.skrabec@gmail.com>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        Chen-Yu Tsai <wens@csie.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Jerome Brunet <jbrunet@baylibre.com>,
        Samuel Holland <samuel@sholland.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Daniel Vetter <daniel@ffwll.ch>, Emma Anholt <emma@anholt.net>,
        David Airlie <airlied@linux.ie>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        =?UTF-8?Q?Noralf_Tr=C3=B8nnes?= <noralf@tronnes.org>,
        Kevin Hilman <khilman@baylibre.com>,
        Neil Armstrong <narmstrong@baylibre.com>,
        linux-sunxi@lists.linux.dev,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Phil Elwell <phil@raspberrypi.com>,
        Mateusz Kwiatkowski <kfyatek+publicgit@gmail.com>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Dave Stevenson <dave.stevenson@raspberrypi.com>,
        "open list:ARM/Amlogic Meson..." <linux-amlogic@lists.infradead.org>,
        DRI Development <dri-devel@lists.freedesktop.org>,
        Dom Cobley <dom@raspberrypi.com>
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Hi Maxime,

On Tue, Aug 16, 2022 at 4:11 PM Maxime Ripard <maxime@cerno.tech> wrote:
> On Tue, Aug 16, 2022 at 03:29:07PM +0200, Geert Uytterhoeven wrote:
> > On Tue, Aug 16, 2022 at 3:20 PM Maxime Ripard <maxime@cerno.tech> wrote:
> > > On Fri, Aug 12, 2022 at 03:25:18PM +0200, Geert Uytterhoeven wrote:
> > > > > --- a/drivers/gpu/drm/drm_connector.c
> > > > > +++ b/drivers/gpu/drm/drm_connector.c
> > > > > @@ -1649,11 +1650,40 @@ EXPORT_SYMBOL(drm_mode_create_tv_margin_properties);
> > > > >   * 0 on success or a negative error code on failure.
> > > > >   */
> > > > >  int drm_mode_create_tv_properties(struct drm_device *dev,
> > > > > +                                 unsigned int supported_tv_norms,
> > > > >                                   unsigned int num_modes,
> > > > >                                   const char * const modes[])
> > > > >  {
> > > > > +       static const struct drm_prop_enum_list tv_norm_values[] = {
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_NTSC_443) - 1, "NTSC-443" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_NTSC_J) - 1, "NTSC-J" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_NTSC_M) - 1, "NTSC-M" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_PAL_60) - 1, "PAL-60" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_PAL_B) - 1, "PAL-B" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_PAL_D) - 1, "PAL-D" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_PAL_G) - 1, "PAL-G" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_PAL_H) - 1, "PAL-H" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_PAL_I) - 1, "PAL-I" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_PAL_M) - 1, "PAL-M" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_PAL_N) - 1, "PAL-N" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_PAL_NC) - 1, "PAL-Nc" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_SECAM_60) - 1, "SECAM-60" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_SECAM_B) - 1, "SECAM-B" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_SECAM_D) - 1, "SECAM-D" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_SECAM_G) - 1, "SECAM-G" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_SECAM_K) - 1, "SECAM-K" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_SECAM_K1) - 1, "SECAM-K1" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_SECAM_L) - 1, "SECAM-L" },
> > > >
> > > > The above are analog standards, with a variable horizontal resolution.
> > > >
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_HD480I) - 1, "hd480i" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_HD480P) - 1, "hd480p" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_HD576I) - 1, "hd576i" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_HD576P) - 1, "hd576p" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_HD720P) - 1, "hd720p" },
> > > > > +               { __builtin_ffs(DRM_MODE_TV_NORM_HD1080I) - 1, "hd1080i" },
> > > >
> > > > The above are digital standards, with a fixed resolution.
> > >
> > > Are they?
> > >
> > > It's not clear to me from looking at nouveau, but I was under the
> > > impression that they were modes for a component output, so CEA 770.3. I
> > > don't have the spec though, so I can't check.
> >
> > Oh right, I forgot about analog HD over component, where you can use
> > other pixel clocks than in the digital standard.
> >
> > > > You seem to have missed "hd1080p"?
> > >
> > > Nobody is using it. If we ever have a driver that uses it I think we can
> > > add it.
> >
> > The PS3 supports 1080p over component
> > https://manuals.playstation.net/document/en/ps3/current/settings/videooutput.html
>
> Yeah, and iirc the Xbox360 did too, but what I meant by nobody is using
> it is that there's no driver using it currently.

OK, it can be added later.

> > > > In addition, "hd720p", "hd080i", and "hd1080p" are available in both 50
> > > > and 60 (actually 59.94) Hz, while "hd1080p" can also use 24 or 25 Hz.
> > >
> > > It looks like nouveau only exposes modes for 480p at 59.94Hz, 576p at
> > > 50Hz, 720p at 60Hz, 1080i at 30Hz.
> >
> > PS3 supports both 50 and 60 Hz (same link above).
>
> I'm probably wary on this, but I'd rather stay at feature parity for
> this series. There's already plenty of occasion to screw up something
> that I'd rather not introduce new stuff I haven't been able to test :)
>
> Provided we can easily extend it to support these additional features of
> course :)
>
> > > > Either you have to add them here (e.g. "hd720p50" and "hd720p60"), or
> > > > handle them through "@<refresh>".  The latter would impact "[PATCH v1
> > > > 09/35] drm/modes: Move named modes parsing to a separate function", as
> > > > currently a named mode and a refresh rate can't be specified both.
> > >
> > > I think the former would make more sense. It simplifies a bit the
> > > parser, and we're going to use a named mode anyway.
> > >
> > > > As "[PATCH v1 34/35] drm/modes: Introduce the tv_mode property as a
> > > > command-line option" uses a separate "tv_mode" option, and not the main
> > > > mode name, I think you want to add them here.
> > >
> > > It's a separate story I think, we could have a named mode hd720p50,
> > > which would be equivalent to 1280x720,tv_mode=hd720p
> >
> > So where's the field rate in "1280x720,tv_mode=hd720p"?
>
> Yeah, sorry I meant 1280x720@50,tv_mode=hd720p

Above you said "I think the former would make more sense", so that
should be "1280x720,tv_mode=hd720p50"?

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