Re: [PATCH] efi: EFI_EARLYCON should depend on EFI

From: Damien Le Moal
Date: Wed Nov 25 2020 - 03:21:30 EST


On Tue, 2020-11-24 at 20:16 +0100, Geert Uytterhoeven wrote:
> CONFIG_EFI_EARLYCON defaults to yes, and thus is enabled on systems that
> do not support EFI, or do not have EFI support enabled, but do satisfy
> the symbol's other dependencies.
>
> While drivers/firmware/efi/ won't be entered during the build phase if
> CONFIG_EFI=n, and drivers/firmware/efi/earlycon.c itself thus won't be
> built, enabling EFI_EARLYCON does force-enable CONFIG_FONT_SUPPORT and
> CONFIG_ARCH_USE_MEMREMAP_PROT, and CONFIG_FONT_8x16, which is
> undesirable.
>
> Fix this by making CONFIG_EFI_EARLYCON depend on CONFIG_EFI.
>
> This reduces kernel size on headless systems by more than 4 KiB.
>
> Fixes: 69c1f396f25b805a ("efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation")
> Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> ---
>  drivers/firmware/efi/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
> index b452cfa2100b401c..1dd1f7784f0888ff 100644
> --- a/drivers/firmware/efi/Kconfig
> +++ b/drivers/firmware/efi/Kconfig
> @@ -270,7 +270,7 @@ config EFI_DEV_PATH_PARSER
>  
>
>  config EFI_EARLYCON
>   def_bool y
> - depends on SERIAL_EARLYCON && !ARM && !IA64
> + depends on EFI && SERIAL_EARLYCON && !ARM && !IA64
>   select FONT_SUPPORT
>   select ARCH_USE_MEMREMAP_PROT
>  
>

Looks good to me.
Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxx>

--
Damien Le Moal
Western Digital