On Wed, Apr 20, 2022 at 09:06:01AM -0300, Fabio Estevam wrote:
> From: Fabio Estevam <festevam@xxxxxxx>
>
> Since commit 358ba762d9f1 ("crypto: caam - enable prediction resistance
> in HRWNG") the following CAAM errors can be seen on i.MX6SX:
>
> caam_jr 2101000.jr: 20003c5b: CCB: desc idx 60: RNG: Hardware error
> hwrng: no data available
>
> This error is due to an incorrect entropy delay for i.MX6SX.
>
> Fix it by increasing the minimum entropy delay for i.MX6SX
> as done in U-Boot:
> https://patchwork.ozlabs.org/project/uboot/patch/20220415111049.2565744-1-gaurav.jain@xxxxxxx/
>
> As explained in the U-Boot patch:
>
> "RNG self tests are run to determine the correct entropy delay.
> Such tests are executed with different voltages and temperatures to identify
> the worst case value for the entropy delay. For i.MX6SX, it was determined
> that after adding a margin value of 1000 the minimum entropy delay should be
> at least 12000."
>
> Cc: <stable@xxxxxxxxxxxxxxx>
> Fixes: 358ba762d9f1 ("crypto: caam - enable prediction resistance in HRWNG")
> Signed-off-by: Fabio Estevam <festevam@xxxxxxx>
> Reviewed-by: Horia Geantă <horia.geanta@xxxxxxx>
> ---
> Changes since v4:
> - Change the function name to needs_entropy_delay_adjustment() - Vabhav
> - Improve the commit log by adding the explanation from the U-Boot
> patch - Vabhav
>
> drivers/crypto/caam/ctrl.c | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)
Patch applied. Thanks.
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
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