Re: [PATCH v2 1/2] fbdev: Split frame buffer support in FB and FB_CORE symbols

[Randy Dunlap <rdunlap@infradead.org>]

Hi,


Does this series apply on top of the previous series or on what?


On 7/1/23 14:44, Javier Martinez Canillas wrote:
> Currently the CONFIG_FB option has to be enabled even if no legacy fbdev
> drivers are needed (e.g: only to have support for framebuffer consoles).
> 
> The DRM subsystem has a fbdev emulation layer, but depends on CONFIG_FB
> and so it can only be enabled if that dependency is enabled as well.
> 
> That means fbdev drivers have to be explicitly disabled if users want to
> enable CONFIG_FB, only to use fbcon and/or the DRM fbdev emulation layer.
> 
> This patch introduces a non-visible CONFIG_FB_CORE symbol that could be
> enabled just to have core support needed for CONFIG_DRM_FBDEV_EMULATION,
> allowing CONFIG_FB to be disabled (and automatically disabling all the
> fbdev drivers).
> 
> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
> ---
> 
> Changes in v2:
> - Keep "depends on FB" for FB_DDC, FB_HECUBA, FB_SVGALIB, FB_MACMODES,
>   FB_BACKLIGHT, FB_MODE_HELPERS and FB_TILEBLITTING (Arnd Bergmann).
> - Don't change the fb.o object name (Arnd Bergmann).
> - Make FB_CORE a non-visible Kconfig symbol instead (Thomas Zimmermann).
> 
>  arch/x86/Makefile                 |  2 +-
>  arch/x86/video/Makefile           |  2 +-
>  drivers/video/console/Kconfig     |  2 +-
>  drivers/video/fbdev/Kconfig       | 40 +++++++++++++++++++------------
>  drivers/video/fbdev/core/Makefile |  2 +-
>  5 files changed, 29 insertions(+), 19 deletions(-)
> 

> diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
> index cecf15418632..da6f7d588f17 100644
> --- a/drivers/video/fbdev/Kconfig
> +++ b/drivers/video/fbdev/Kconfig
> @@ -6,8 +6,12 @@
>  config FB_NOTIFY
>  	bool
>  
> +menuconfig FB_CORE
> +	tristate "Core support for frame buffer devices"
> +

I could be reading this incorrectly, but FB_CORE does not appear to
be a non-visible Kconfig symbol here.

>  menuconfig FB
> -	tristate "Support for frame buffer devices"
> +	tristate "Support for frame buffer device drivers"
> +	select FB_CORE
>  	select FB_NOTIFY
>  	select VIDEO_CMDLINE
>  	help

thanks.
-- 
~Randy