From: Stanimir Varbanov Subject: Re: [PATCH 3/3] hwrng: msm - Add support for prng v2 Date: Fri, 22 Jun 2018 18:33:40 +0300 Message-ID: <015f1c8d-553c-3d54-c7c6-34bbb4fcd1a0@linaro.org> References: <20180618141259.23141-1-vkoul@kernel.org> <20180618141259.23141-4-vkoul@kernel.org> <20180619142853.wgi5easw4zv6ttrb@gondor.apana.org.au> <966e9cd4-70a3-8d54-df0f-16df3df45fb5@linaro.org> <20180621101506.rnklbtapvfdev4xb@gondor.apana.org.au> <20180621115312.rfmbitrhqi44wu5w@gondor.apana.org.au> <6782b1c0-ea94-b07c-2fae-3fe3223bb22a@linaro.org> <20180622143829.rd2ys6ci7q3aupst@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: Vinod Koul , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, Matt Mackall , Arnd Bergmann , Greg Kroah-Hartman , linux-arm-msm@vger.kernel.org, Vinod Koul To: Herbert Xu Return-path: In-Reply-To: <20180622143829.rd2ys6ci7q3aupst@gondor.apana.org.au> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org Hi, On 06/22/2018 05:38 PM, Herbert Xu wrote: > On Fri, Jun 22, 2018 at 11:27:59AM +0300, Stanimir Varbanov wrote: >> Hi Herbert, >> >> On 06/21/2018 02:53 PM, Herbert Xu wrote: >>> On Thu, Jun 21, 2018 at 02:27:10PM +0300, Stanimir Varbanov wrote: >>>> >>>> OK, I just wanted to say that it is _not_ PRNG and the register names >>>> gives us wrong impression. >>> >>> So does it generate one bit of output for each bit of hardware- >>> generated entropy like /dev/random? Or does it use a hardware- >>> generated seed to power a PRNG? >> >> I believe it is the second one. Isn't the second one SP 800-90A? > > In that case it should switch over to algif_rng. OK, what about the rest drivers in drivers/char/hw_random? Are they all true RNG? -- regards, Stan