Re: [PATCH] crypto: caam - optimize RNG sample size

From: Herbert Xu
Date: Fri Jun 23 2023 - 04:21:40 EST


On Mon, Jun 12, 2023 at 10:30:42AM +0200, meenakshi.aggarwal@xxxxxxx wrote:
> From: Meenakshi Aggarwal <meenakshi.aggarwal@xxxxxxx>
>
> TRNG "sample size" (the total number of entropy samples that will be taken
> during entropy generation) default / POR value is very conservatively
> set to 2500.
>
> Let's set it to 512, the same as the caam driver in U-boot
> (drivers/crypto/fsl_caam.c) does.
>
> This solves the issue of RNG performance dropping after a suspend/resume
> cycle on parts where caam loses power, since the initial U-boot setttings
> are lost and kernel does not restore them when resuming.
>
> Note: when changing the sample size, the self-test parameters need to be
> updated accordingly.
>
> Signed-off-by: Horia Geantă <horia.geanta@xxxxxxx>
> Signed-off-by: Meenakshi Aggarwal <meenakshi.aggarwal@xxxxxxx>
> ---
> drivers/crypto/caam/ctrl.c | 52 +++++++++++++++++++++++---------------
> drivers/crypto/caam/regs.h | 14 ++++++++--
> 2 files changed, 44 insertions(+), 22 deletions(-)

Patch applied. Thanks.
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
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