[PATCH v2] caam: bugfix CAAM error on startup

[Tim Harvey]

On Fri, May 30, 2025 at 5:13 AM Fabio Estevam <festevam at gmail.com> wrote:
>
> On Fri, May 30, 2025 at 9:09 AM Fabio Estevam <festevam at gmail.com> wrote:
>
> > u-boot=> rng 0 10
> > Reading RNG failed
> > u-boot=> rng 0 10
> > 00000000: 27 42 f0 b8 92 c8 ca 29 6f 6a c3 98 ff 61 2b ae  'B.....)oj...a+.
> > u-boot=> rng 0 10
> > 00000000: 48 fb 52 44 29 ea 83 f9 a4 1d 68 20 82 c5 af b5  H.RD).....h ....
> > u-boot=> rng 0 10
> > 00000000: 92 63 76 fc 1c 12 4b cd 68 50 8c fa 2b 51 21 50  .cv...K.hP..+Q!P
> > u-boot=> rng 0 10
> >
> > (always hang in the fifth attempt)
>
> Correction: it does not hang in the fifth attempt. It works on all
> subsequent calls, as Tim reported.

Fabio,

Thanks for verifying from your end. I ran into this when I was testing
lwIP HTTPS as it causes anything that uses dm_rng to fail the first
time (such as HTTPS).

I have never seen the error Olaf reports 'SEC0:  RNG4 SH0
instantiation failed with error 0xffffffff' and I'm not clear what SoC
he saw that on or how rare it was. From the commit log it seemed like
a theoretical fix that may have not been the right thing to do.

Best regards,

Tim