Re: [PATCH v1 05/35] drm/connector: Add TV standard property

[Geert Uytterhoeven <geert@linux-m68k.org>]

Hi Maxime,

On Fri, Jul 29, 2022 at 6:35 PM Maxime Ripard <maxime@cerno.tech> wrote:
> The TV mode property has been around for a while now to select and get the
> current TV mode output on an analog TV connector.
>
> Despite that property name being generic, its content isn't and has been
> driver-specific which makes it hard to build any generic behaviour on top
> of it, both in kernel and user-space.
>
> Let's create a new bitmask tv norm property, that can contain any of the
> analog TV standards currently supported by kernel drivers. Each driver can
> then pass in a bitmask of the modes it supports.
>
> We'll then be able to phase out the older tv mode property.
>
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>

Thanks for your patch!

> --- 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.

You seem to have missed "hd1080p"?

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.
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.

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.

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