Re: [PATCH v3 1/6] LoongArch: efi: Provide sysfb_primary_display for screen_info users

[Thomas Zimmermann <tzimmermann@suse.de>]

Hi

Am 10.11.26 um 09:56 schrieb wuqianhai@loongson.cn:
> From: wuqianhai <wuqianhai@loongson.cn>
>
> LoongArch defines and initializes sysfb_primary_display only when
> CONFIG_SYSFB or CONFIG_EFI_EARLYCON is enabled.  The PCI VGA arbiter and
> the framebuffer console need the firmware framebuffer information through
> screen_info whenever CONFIG_SCREEN_INFO is enabled, even if neither of
> those options is set.
>
> Drop the guards so sysfb_primary_display is always defined and
> initialized, and its EFI stub alias is always provided, mirroring x86.
> This avoids selecting SYSFB just to obtain the symbol.
>
> Signed-off-by: wuqianhai <wuqianhai@loongson.cn>
> ---
>   arch/loongarch/kernel/efi.c        | 5 +----
>   arch/loongarch/kernel/image-vars.h | 2 --
>   2 files changed, 1 insertion(+), 6 deletions(-)
>
> diff --git a/arch/loongarch/kernel/efi.c b/arch/loongarch/kernel/efi.c
> index 69dd83f8082f..e491a82b2e0d 100644
> --- a/arch/loongarch/kernel/efi.c
> +++ b/arch/loongarch/kernel/efi.c
> @@ -74,10 +74,8 @@ bool efi_poweroff_required(void)
>   
>   unsigned long __initdata primary_display_table = EFI_INVALID_TABLE_ADDR;
>   
> -#if defined(CONFIG_SYSFB) || defined(CONFIG_EFI_EARLYCON)
>   struct sysfb_display_info sysfb_primary_display __section(".data");
>   EXPORT_SYMBOL_GPL(sysfb_primary_display);
> -#endif

I never understood how linking works. I would assume that this symbol 
interferes with the shared one at [1]. Can't loongarch use that as well?

[1] 
https://elixir.bootlin.com/linux/v7.3.1/source/drivers/firmware/efi/efi-init.c#L64

Best regards
Thomas

>   
>   static void __init init_primary_display(void)
>   {
> @@ -129,8 +127,7 @@ void __init efi_init(void)
>   
>   	set_bit(EFI_CONFIG_TABLES, &efi.flags);
>   
> -	if (IS_ENABLED(CONFIG_EFI_EARLYCON) || IS_ENABLED(CONFIG_SYSFB))
> -		init_primary_display();
> +	init_primary_display();
>   
>   	if (boot_memmap == EFI_INVALID_TABLE_ADDR)
>   		return;
> diff --git a/arch/loongarch/kernel/image-vars.h b/arch/loongarch/kernel/image-vars.h
> index e557ebd46c2b..4d1d7978553a 100644
> --- a/arch/loongarch/kernel/image-vars.h
> +++ b/arch/loongarch/kernel/image-vars.h
> @@ -11,9 +11,7 @@ __efistub_strcmp		= strcmp;
>   __efistub_kernel_entry		= kernel_entry;
>   __efistub_kernel_asize		= kernel_asize;
>   __efistub_kernel_fsize		= kernel_fsize;
> -#if defined(CONFIG_EFI_EARLYCON) || defined(CONFIG_SYSFB)
>   __efistub_sysfb_primary_display	= sysfb_primary_display;
> -#endif
>   
>   #endif
>   

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Stefan Gaiser, Jochen Jaser, Abhinav Puri, (HRB 36809, AG Nürnberg)