Re: [PATCH] apple_m1_defconfig: Bump CONFIG_LMB_MAX_REGIONS to 64

[Mark Kettenis <mark.kettenis@xs4all.nl>]

> From: Janne Grunau <j@jannau.net>
> Date: Mon, 13 Mar 2023 14:54:32 +0100
> 
> Apple silicon SoCs have numerous embedded co-processors with pre-loaded
> firmware. The co-processors text and data sections need to be mapped via
> DART iommus controlled by the main processor. Those sections are
> exported as reserved-memory. Bump CONFIG_LMB_MAX_REGIONS from 8 to 64 to
> deal with the large amount of reserved-memory regions.

We recently bumped the default for CONFIG_LMB_MAX_REGIONS from 8 to
16, but 64 would be a safer value for this platform as there are more
co-processor drivers in the pipeline that may add reserved-memory
regions.  These machines have plenty of memory.

> Signed-off-by: Janne Grunau <j@jannau.net>

Reviewed-by: Mark Kettenis <kettenis@openbsd.org>

> ---
>  configs/apple_m1_defconfig | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/configs/apple_m1_defconfig b/configs/apple_m1_defconfig
> index b4ecf73cbc78..755560971e57 100644
> --- a/configs/apple_m1_defconfig
> +++ b/configs/apple_m1_defconfig
> @@ -21,3 +21,4 @@ CONFIG_SYS_WHITE_ON_BLACK=y
>  CONFIG_NO_FB_CLEAR=y
>  CONFIG_VIDEO_SIMPLE=y
>  # CONFIG_GENERATE_SMBIOS_TABLE is not set
> +CONFIG_LMB_MAX_REGIONS=64
> 
> ---
> base-commit: 6c1cdf158c4f3ccc8c5f9552f049a3386899dcd2
> change-id: 20230313-apple_m1_defconfig_lmb_max_regions-a18f5612d3c3
> 
> Best regards,
> -- 
> Janne Grunau <j@jannau.net>
> 
>