Re: [PATCH v7 0/3] hwrng: add hwrng support for Rockchip RK3568

Anand Moon
2024-07-17T05:06:40Z

Hi All,

On Wed, 17 Jul 2024 at 08:29, Chen-Yu Tsai <wens@kernel.org> wrote:
>
> On Wed, Jul 17, 2024 at 10:25 AM Daniel Golle <daniel@makrotopia.org> wrote:
> >
> > On Tue, Jul 16, 2024 at 07:19:35PM +0200, Diederik de Haas wrote:
> > > On Tuesday, 16 July 2024 18:53:43 CEST Diederik de Haas wrote:
> > > > rngtest: FIPS 140-2(2001-10-10) Long run: 0
> > >
> > > I don't know if it means something, but I noticed that I have
> > > ``Long run: 0`` with all my poor results,
> > > while Chen-Yu had ``Long run: 1``.
> > >
> > > Different SoC (RK3399), but Anand had ``Long run: 0`` too on their
> > > very poor result (100% failure):
> > > https://lore.kernel.org/linux-rockchip/CANAwSgTTzZOwBaR9zjJ5VMpxm5BydtW6rB2S7jg+dnoX8hAoWg@mail.gmail.com/
> >
> > The conclusions I draw from that rather ugly situation are:
> > - The hwrng should not be enabled by default, but it should by done
> > for each board on which it is known to work well.
> > - RK_RNG_SAMPLE_CNT as well as the assumed rng quality should be
> > defined in DT for each board:
> > * introduce new 'rochchip,rng-sample-count' property
> > * read 'quality' property already used for timeriomem_rng
> >
> > I will prepare a follow-up patch taking those conclusions into account.
> >
> > Just for completeness, here my test result on the NanoPi R5C:
> > root@OpenWrt:~# cat /dev/hwrng | rngtest -c 1000
> > rngtest 6.15
> > Copyright (c) 2004 by Henrique de Moraes Holschuh
> > This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
> >
> > rngtest: starting FIPS tests...
> > rngtest: bits received from input: 20000032
> > rngtest: FIPS 140-2 successes: 875
> > rngtest: FIPS 140-2 failures: 125
> > rngtest: FIPS 140-2(2001-10-10) Monobit: 123
> > rngtest: FIPS 140-2(2001-10-10) Poker: 5
> > rngtest: FIPS 140-2(2001-10-10) Runs: 4
> > rngtest: FIPS 140-2(2001-10-10) Long run: 0
> > rngtest: FIPS 140-2(2001-10-10) Continuous run: 0
> > rngtest: input channel speed: (min=85.171; avg=141.102; max=4882812.500)Kibits/s
> > rngtest: FIPS tests speed: (min=17.809; avg=19.494; max=60.169)Mibits/s
> > rngtest: Program run time: 139628605 microseconds
>
> I doubt this is per-board. The RNG is inside the SoC, so it could be a chip
> quality thing. On the RK3399 we also saw wildly varying results.
>
I feel the latest rng-tool only supports Intel platform x86_64 and i386.
It has no proper support for Arm64 and Armv7
It is heavily modified for the X86 platform
so it's not suitable for testing on other platforms.

If we enable HWRNG on all the Rockchip platforms it will be better.

[1] https://github.com/nhorman/rng-tools

> ChenYu

Thanks

-Anand