Messages in this thread | | | Date | Wed, 23 Jul 2014 22:13:09 +0800 | From | Herbert Xu <> | Subject | Re: [PATCH 3/3] crypto: Add Allwinner Security System crypto accelerator |
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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?
Cheers, -- 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
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