Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1670239 > unrolled thread

Re: [PATCH v2 0/3] add support of hardware random generator on MediaTek MT7622

Started byHerbert Xu <herbert@gondor.apana.org.au>
First post2017-06-20 05:50 +0200
Last post2017-06-20 18:10 +0200
Articles 4 — 3 participants

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  Re: [PATCH v2 0/3] add support of hardware random generator on  MediaTek MT7622 Herbert Xu <herbert@gondor.apana.org.au> - 2017-06-20 05:50 +0200
    Re: [PATCH v2 0/3] add support of hardware random generator on  MediaTek MT7622 Sean Wang <sean.wang@mediatek.com> - 2017-06-20 16:30 +0200
      Re: [PATCH v2 0/3] add support of hardware random generator on  MediaTek MT7622 Torsten Duwe <duwe@suse.de> - 2017-06-20 17:00 +0200
        Re: [PATCH v2 0/3] add support of hardware random generator on  MediaTek MT7622 Sean Wang <sean.wang@mediatek.com> - 2017-06-20 18:10 +0200

#1670239 — Re: [PATCH v2 0/3] add support of hardware random generator on MediaTek MT7622

FromHerbert Xu <herbert@gondor.apana.org.au>
Date2017-06-20 05:50 +0200
SubjectRe: [PATCH v2 0/3] add support of hardware random generator on MediaTek MT7622
Message-ID<tUikW-3gU-11@gated-at.bofh.it>
On Mon, Jun 12, 2017 at 11:56:53PM +0800, sean.wang@mediatek.com wrote:
> From: Sean Wang <sean.wang@mediatek.com>
> 
> Changes since v1:
> - update the bindings with the specific "mediatek,mt7622-rng"
>   instead of the generic one as "mediatek,generic-rng"
> 
> The series add support of hardware RNG on MediaTek MT7622 and
> , runtime PM support and add me as the maintainer for the existing
> and following chipset.
> 
> Sean Wang (3):
>   dt-bindings: rng: add MediaTek MT7622 Hardware Random Generator
>     bindings
>   hwrng: mtk - add runtime PM support
>   MAINTAINERS: add entry for MediaTek Random Number Generator

All applied.  Thanks.
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

[toc] | [next] | [standalone]

#1670823

FromSean Wang <sean.wang@mediatek.com>
Date2017-06-20 16:30 +0200
Message-ID<tUskh-1iC-7@gated-at.bofh.it>
In reply to#1670239
Hi Herbert,

thanks for effort reviewing on those patches.

By the way, also loop in Torsten

Could you kindly guide me how to determine appropriate 
rng->ops.quality value used by the driver?

There is less clues since the value is not being set in
most drivers. But good value decided would allow feeding
fresh entropy data with the hwrng so i would like add it
in the next patch.

I have tested with rngtest on mtk-cir and the result is got as
the below log shown.  If the rngtest always gives the result for
success rate over 99.8%, can I set the rng->ops.quality 998?

rngtest: starting FIPS tests...
rngtest: bits received from input: 20000032
rngtest: FIPS 140-2 successes: 998
rngtest: FIPS 140-2 failures: 2
rngtest: FIPS 140-2(2001-10-10) Monobit: 1
rngtest: FIPS 140-2(2001-10-10) Poker: 0
rngtest: FIPS 140-2(2001-10-10) Runs: 1
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=715.902; avg=3846.234;
max=3906250.000)Kibits/s
rngtest: FIPS tests speed: (min=35.453; avg=37.862; max=38.300)Mibits/s
rngtest: Program run time: 5591758 microseconds

rngtest: starting FIPS tests...
rngtest: bits received from input: 20000032
rngtest: FIPS 140-2 successes: 1000
rngtest: FIPS 140-2 failures: 0
rngtest: FIPS 140-2(2001-10-10) Monobit: 0
rngtest: FIPS 140-2(2001-10-10) Poker: 0
rngtest: FIPS 140-2(2001-10-10) Runs: 0
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=715.588; avg=4424.787;
max=4882812.500)Kibits/s
rngtest: FIPS tests speed: (min=35.785; avg=37.859; max=38.223)Mibits/s
rngtest: Program run time: 4947950 microseconds



On Tue, 2017-06-20 at 11:40 +0800, Herbert Xu wrote:
> On Mon, Jun 12, 2017 at 11:56:53PM +0800, sean.wang@mediatek.com wrote:
> > From: Sean Wang <sean.wang@mediatek.com>
> > 
> > Changes since v1:
> > - update the bindings with the specific "mediatek,mt7622-rng"
> >   instead of the generic one as "mediatek,generic-rng"
> > 
> > The series add support of hardware RNG on MediaTek MT7622 and
> > , runtime PM support and add me as the maintainer for the existing
> > and following chipset.
> > 
> > Sean Wang (3):
> >   dt-bindings: rng: add MediaTek MT7622 Hardware Random Generator
> >     bindings
> >   hwrng: mtk - add runtime PM support
> >   MAINTAINERS: add entry for MediaTek Random Number Generator
> 
> All applied.  Thanks.

[toc] | [prev] | [next] | [standalone]

#1670841

FromTorsten Duwe <duwe@suse.de>
Date2017-06-20 17:00 +0200
Message-ID<tUsNk-1v3-23@gated-at.bofh.it>
In reply to#1670823
On Tue, Jun 20, 2017 at 10:21:17PM +0800, Sean Wang wrote:
> Hi Herbert,
> 
> thanks for effort reviewing on those patches.
> 
> By the way, also loop in Torsten
> 
> Could you kindly guide me how to determine appropriate 
> rng->ops.quality value used by the driver?
> 
> I have tested with rngtest on mtk-cir and the result is got as
> the below log shown.  If the rngtest always gives the result for
> success rate over 99.8%, can I set the rng->ops.quality 998?
> 
> rngtest: starting FIPS tests...
> rngtest: bits received from input: 20000032
> rngtest: FIPS 140-2 successes: 998
> rngtest: FIPS 140-2 failures: 2

No! You'd have to determine the failure threshold of the test and
apply some math to find a lower boundary of your RNG's entropy.

What the quality is for: your RNG produces bits, but not all of them
are completely independent of each other i.e. not completely random.
So you simply lower the quality rating to express the net entropy
contained in the data stream.

	Torsten

[toc] | [prev] | [next] | [standalone]

#1670910

FromSean Wang <sean.wang@mediatek.com>
Date2017-06-20 18:10 +0200
Message-ID<tUtT4-2pP-23@gated-at.bofh.it>
In reply to#1670841
On Tue, 2017-06-20 at 16:59 +0200, Torsten Duwe wrote:
> On Tue, Jun 20, 2017 at 10:21:17PM +0800, Sean Wang wrote:
> > Hi Herbert,
> > 
> > thanks for effort reviewing on those patches.
> > 
> > By the way, also loop in Torsten
> > 
> > Could you kindly guide me how to determine appropriate 
> > rng->ops.quality value used by the driver?
> > 
> > I have tested with rngtest on mtk-cir and the result is got as
> > the below log shown.  If the rngtest always gives the result for
> > success rate over 99.8%, can I set the rng->ops.quality 998?
> > 
> > rngtest: starting FIPS tests...
> > rngtest: bits received from input: 20000032
> > rngtest: FIPS 140-2 successes: 998
> > rngtest: FIPS 140-2 failures: 2
> 
> No! You'd have to determine the failure threshold of the test and
> apply some math to find a lower boundary of your RNG's entropy.
> 
> What the quality is for: your RNG produces bits, but not all of them
> are completely independent of each other i.e. not completely random.
> So you simply lower the quality rating to express the net entropy
> contained in the data stream.
> 
> 	Torsten
> 


Hi Torsten,

Understood, appreciate your quick and clear explanation.
 
For the math, is there existing any well-known or recommended
open source software assisting identify the lower boundary of
RNG entropy? I think the logic should be common for all RNGs.

thanks again

	Sean


	Sean

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web