From: Corentin LABBE <clabbe.montjoie@gmail.com>
To: Marek Vasut <marex@denx.de>, Herbert Xu <herbert@gondor.apana.org.au>
Cc: robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com,
ijc+devicetree@hellion.org.uk, galak@codeaurora.org,
rdunlap@infradead.org, maxime.ripard@free-electrons.com,
linux@arm.linux.org.uk, davem@davemloft.net,
grant.likely@linaro.org, devicetree@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org
Subject: Re: [PATCH 3/3] crypto: Add Allwinner Security System crypto accelerator
Date: Wed, 23 Jul 2014 20:52:12 +0200 [thread overview]
Message-ID: <53D0045C.6090605@gmail.com> (raw)
In-Reply-To: <201407231751.02050.marex@denx.de>
Le 23/07/2014 17:51, Marek Vasut a écrit :
> On Wednesday, July 23, 2014 at 04:13:09 PM, Herbert Xu wrote:
>> On Wed, Jul 23, 2014 at 04:07:20PM +0200, Marek Vasut wrote:
>>> On Wednesday, July 23, 2014 at 03:57:35 PM, Herbert Xu wrote:
>>>> On Sat, May 24, 2014 at 02:00:03PM +0200, Marek Vasut wrote:
>>>>>> + }
>>>>>> +#endif
>>>>>> +
>>>>>> +#ifdef CONFIG_CRYPTO_DEV_SUNXI_SS_MD5
>>>>>> + err = crypto_register_shash(&sunxi_md5_alg);
>>>>>
>>>>> Do not use shash for such device. This is clearly and ahash (and
>>>>> async in general) device. The rule of a thumb here is that you use
>>>>> sync algos only for devices which have dedicated instructions for
>>>>> computing the transformation. For devices which are attached to some
>>>>> kind of bus, you use async algos (ahash etc).
>>>>
>>>> I'm sorry that I didn't catch this earlier but there is no such
>>>> rule.
>>>>
>>>> Unless you need the async interface you should stick to the sync
>>>> interfaces for the sake of simplicity.
>>>>
>>>> We have a number of existing drivers that are synchronous but
>>>> using the async interface. They should either be converted
>>>> over to the sync interface or made interrupt-driven if possible.
>>>
>>> Sure, but this device is interrupt driven and uses DMA to feed the crypto
>>> engine, therefore async, right ?
>>
>> If it's interrupt-driven, then yes it would certainly make sense to
>> be async. But all I see is polling in the latest posting, was the
>> first version different?
>
> I stand corrected then, sorry.
>
> Is it possible to use DMA to feed the crypto accelerator, Corentin?
>
> Best regards,
> Marek Vasut
>
Yes, DMA is possible and will be implemented soon.
So if I have well understood, I keep using async interface.
next prev parent reply other threads:[~2014-07-23 18:52 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-22 15:09 crypto: Add Allwinner Security System crypto accelerator LABBE Corentin
2014-05-22 15:09 ` [PATCH 1/3] dt: Add DT bindings documentation for SUNXI Security System LABBE Corentin
2014-05-24 11:21 ` Marek Vasut
2014-05-24 19:20 ` Tomasz Figa
2014-05-24 19:43 ` Marek Vasut
2014-05-24 19:51 ` Tomasz Figa
2014-05-24 19:59 ` Marek Vasut
2014-05-25 13:09 ` Maxime Ripard
2014-05-25 13:07 ` Maxime Ripard
2014-05-22 15:09 ` [PATCH 2/3] ARM: sun7i: dt: Add Security System to A20 SoC DTS LABBE Corentin
2014-05-24 11:23 ` Marek Vasut
2014-05-22 15:09 ` [PATCH 3/3] crypto: Add Allwinner Security System crypto accelerator LABBE Corentin
2014-05-22 15:28 ` Arnd Bergmann
2014-05-22 18:13 ` Corentin LABBE
2014-05-23 10:46 ` Arnd Bergmann
2014-05-24 11:26 ` Marek Vasut
2014-05-24 12:00 ` Marek Vasut
2014-05-25 11:58 ` Corentin LABBE
2014-05-25 14:30 ` Marek Vasut
2014-07-23 13:57 ` Herbert Xu
2014-07-23 14:07 ` Marek Vasut
2014-07-23 14:13 ` Herbert Xu
2014-07-23 15:51 ` Marek Vasut
2014-07-23 18:52 ` Corentin LABBE [this message]
2014-07-23 19:38 ` Marek Vasut
2014-07-24 1:40 ` Herbert Xu
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