From: "Jason A. Donenfeld" <Jason@zx2c4.com>
To: Olivia Mackall <olivia@selenic.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
Rob Herring <robh+dt@kernel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
Heiko Stuebner <heiko@sntech.de>,
Philipp Zabel <p.zabel@pengutronix.de>,
Lin Jinhan <troy.lin@rock-chips.com>,
"open list:HARDWARE RANDOM NUMBER GENERATOR CORE"
<linux-crypto@vger.kernel.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
"moderated list:ARM/Rockchip SoC support"
<linux-arm-kernel@lists.infradead.org>,
"open list:ARM/Rockchip SoC support"
<linux-rockchip@lists.infradead.org>,
open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 2/3] hwrng: add Rockchip SoC hwrng driver
Date: Mon, 5 Dec 2022 22:41:22 +0100 [thread overview]
Message-ID: <Y45lguC4ZiniiWS/@zx2c4.com> (raw)
In-Reply-To: <Y45j/hd2MnnXzcAo@aurel32.net>
Hi Aurelien,
On Mon, Dec 05, 2022 at 10:34:54PM +0100, Aurelien Jarno wrote:
> Well I am not sure it really matters. 90% is actually conservative, it's
> the worst case I have seen, rounded down. However I often get much
> better quality, see for instance the following run:
>
> | 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: entropy source drained
> | rngtest: bits received from input: 16777216
> | rngtest: FIPS 140-2 successes: 819
> | rngtest: FIPS 140-2 failures: 19
> | rngtest: FIPS 140-2(2001-10-10) Monobit: 17
> | rngtest: FIPS 140-2(2001-10-10) Poker: 0
> | rngtest: FIPS 140-2(2001-10-10) Runs: 2
> | rngtest: FIPS 140-2(2001-10-10) Long run: 2
> | rngtest: FIPS 140-2(2001-10-10) Continuous run: 0
> | rngtest: input channel speed: (min=132.138; avg=137.848; max=147.308)Kibits/s
> | rngtest: FIPS tests speed: (min=16.924; avg=20.272; max=20.823)Mibits/s
> | rngtest: Program run time: 119647459 microseconds
>
> Does the exact value has an importance there? I thought it was just
> important to not overestimate the quality.
That's the right principle. I just worry about estimating it like that
from looking at the output, rather than being derived from some
knowledge about the hardware. Maybe 50% (quality=512) is more
reasonable, so that it collects two bits for every one?
Jason
next prev parent reply other threads:[~2022-12-05 21:41 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-28 18:47 [PATCH v2 0/3] hwrng: add hwrng support for Rockchip RK3568 Aurelien Jarno
2022-11-28 18:47 ` [PATCH v2 1/3] dt-bindings: RNG: Add Rockchip RNG bindings Aurelien Jarno
2022-11-29 9:24 ` Krzysztof Kozlowski
2022-12-02 19:20 ` Aurelien Jarno
2022-12-03 10:21 ` Krzysztof Kozlowski
2022-11-28 18:47 ` [PATCH v2 2/3] hwrng: add Rockchip SoC hwrng driver Aurelien Jarno
2022-11-29 9:33 ` Krzysztof Kozlowski
2022-12-02 19:30 ` Aurelien Jarno
2022-12-05 13:13 ` Jason A. Donenfeld
2022-12-05 13:30 ` Jason A. Donenfeld
2022-12-05 21:34 ` Aurelien Jarno
2022-12-05 21:41 ` Jason A. Donenfeld [this message]
2022-11-28 18:47 ` [PATCH v2 3/3] arm64: dts: rockchip: add DT entry for RNG to RK356x Aurelien Jarno
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