[PATCH 1/2] drm/panel: remove unnecessary dependencies

[arnd@arndb.de (Arnd Bergmann)]

On Thursday 12 June 2014 16:50:15 Russell King wrote:
> DRM_PANEL_LD9040 and DRM_PANEL_S6E8AA0 both explicitly depended on
> DRM_PANEL && DRM.  This is nonsense for two reasons:
> 
> (a) DRM_PANEL already depends on DRM, so DRM_PANEL can not be enabled
> without DRM first being enabled.  Hence the && DRM is useless.
> 
> (b) These two configs are already beneath a menu which depends on
> DRM_PANEL being enabled; these options will not be visible without
> DRM_PANEL already being enabled.
> 
> Let's just remove this unnecessary verbosity.
> 
> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Unfortunately, this is wrong, because the current expression
exploits one of the finer details of Kconfig syntax:

>  drivers/gpu/drm/panel/Kconfig | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> index 4ec874da5668..44aea730b3aa 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -18,14 +18,12 @@ config DRM_PANEL_SIMPLE
>  
>  config DRM_PANEL_LD9040
>         tristate "LD9040 RGB/SPI panel"
> -       depends on DRM && DRM_PANEL
>         depends on OF
>         select SPI
>         select VIDEOMODE_HELPERS
>  
>  config DRM_PANEL_S6E8AA0
>         tristate "S6E8AA0 DSI video mode panel"
> -       depends on DRM && DRM_PANEL
>         depends on OF
>         select DRM_MIPI_DSI
>         select VIDEOMODE_HELPERS

DRM_PANEL is bool, while DRM is tristate. If DRM=m and DRM_PANEL=y,
these two options can only be 'n' or 'm' but not 'y' with the current
code, but they can be 'y' if you drop the explicit DRM dependency,
which will cause a link failure.

The DRM_PANEL dependency can be removed, it is indeed unnecessary.

	Arnd