[PATCH] drm: rcar-du: Fix Kconfig dependency between RCAR_DU and RCAR_MIPI_DSI

[Geert Uytterhoeven]

Hi Laurent,

On Sun, Oct 2, 2022 at 12:06 AM Laurent Pinchart
<laurent.pinchart+renesas at ideasonboard.com> wrote:
> When the R-Car MIPI DSI driver was added, it was a standalone encoder
> driver without any dependency to or from the R-Car DU driver. Commit
> 957fe62d7d15 ("drm: rcar-du: Fix DSI enable & disable sequence") then
> added a direct call from the DU driver to the MIPI DSI driver, without
> updating Kconfig to take the new dependency into account. Fix it the
> same way that the LVDS encoder is handled.
>
> Fixes: 957fe62d7d15 ("drm: rcar-du: Fix DSI enable & disable sequence")
> Reported-by: kernel test robot <lkp at intel.com>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas at ideasonboard.com>

Thanks for your patch, which is now commit a830a15678593948
("drm: rcar-du: Fix Kconfig dependency between RCAR_DU
and RCAR_MIPI_DSI") in v6.1-rc5.

> --- a/drivers/gpu/drm/rcar-du/Kconfig
> +++ b/drivers/gpu/drm/rcar-du/Kconfig
> @@ -44,12 +44,17 @@ config DRM_RCAR_LVDS
>         select OF_FLATTREE
>         select OF_OVERLAY
>
> +config DRM_RCAR_USE_MIPI_DSI
> +       bool "R-Car DU MIPI DSI Encoder Support"
> +       depends on DRM_BRIDGE && OF
> +       default DRM_RCAR_DU

This means this driver is now enabled by default on systems that do not
have the MIPI DSI Encoder (e.g. R-Car Gen2), and that we should probably
disable it explicitly in shmobile_defconfig.  Is that intentional?

> +       help
> +         Enable support for the R-Car Display Unit embedded MIPI DSI encoders.
> +
>  config DRM_RCAR_MIPI_DSI
> -       tristate "R-Car DU MIPI DSI Encoder Support"
> -       depends on DRM && DRM_BRIDGE && OF
> +       def_tristate DRM_RCAR_DU
> +       depends on DRM_RCAR_USE_MIPI_DSI
>         select DRM_MIPI_DSI
> -       help
> -         Enable support for the R-Car Display Unit embedded MIPI DSI encoders.
>
>  config DRM_RCAR_VSP
>         bool "R-Car DU VSP Compositor Support" if ARM

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