[PATCH v6] rockchip: board: Increase rng-seed size to make it sufficient for modern Linux

[Quentin Schulz]

Hi Alex,

On 10/16/24 12:02 PM, Alex Shumsky wrote:
> Increase rng-seed size to make Linux happy and initialize rng pool instantly.
> Linux 5.19+ requires 32 bytes of entropy to initialize random pool, but u-boot
> currently provides only 8 bytes.
> Linux 5.18 and probably some versions before it used to require 64 bytes.
> Bump min value to 64 bytes to be on a safe side.
> 
> Boot with 8 byte rng-seed (Linux 6.11):
>      # dmesg | grep crng
>      [   12.089286] random: crng init done
> Boot with 32 byte rng-seed (Linux 6.11):
>      # dmesg | grep crng
>      [    0.000000] random: crng init done
> 
> Linux source references:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/char/random.c?h=v5.19#n551
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/char/random.c?h=v5.18#n236
> 
> Signed-off-by: Alex Shumsky <alexthreed at gmail.com>
> Fixes: d2048bafae40 ("rockchip: board: Add board_rng_seed() for all Rockchip devices")
> Reviewed-by: Dragan Simic <dsimic at manjaro.org>
> Reviewed-by: Marek Vasut <marex at denx.de>

Reviewed-by: Quentin Schulz <quentin.schulz at cherry.de>

Thanks!
Quentin