Return-path: Received: from smtp.codeaurora.org ([198.145.29.96]:57480 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752762AbcHOLBQ (ORCPT ); Mon, 15 Aug 2016 07:01:16 -0400 From: Kalle Valo To: "Pan\, Miaoqing" Cc: Stephan Mueller , Ted Tso , "Sepehrdad\, Pouyan" , "herbert\@gondor.apana.org.au" , "linux-kernel\@vger.kernel.org" , "linux-crypto\@vger.kernel.org" , ath9k-devel , "linux-wireless\@vger.kernel.org" , "ath9k-devel\@lists.ath9k.org" , "Jason Cooper" Subject: Re: [PATCH v2] RANDOM: ATH9K RNG delivers zero bits of entropy References: <34197429.2CvoIfft9B@positron.chronox.de> <1654172.XfclnXhRmn@positron.chronox.de> <657897b90b8344eeab10d7a0f604988d@aptaiexm02f.ap.qualcomm.com> Date: Mon, 15 Aug 2016 14:01:09 +0300 In-Reply-To: <657897b90b8344eeab10d7a0f604988d@aptaiexm02f.ap.qualcomm.com> (Miaoqing Pan's message of "Mon, 8 Aug 2016 02:03:36 +0000") Message-ID: <87wpji70ui.fsf@purkki.adurom.net> (sfid-20160815_130136_664707_5D8B424D) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-wireless-owner@vger.kernel.org List-ID: "Pan, Miaoqing" writes: > The entropy was evaluated by crypto expert, the analysis report show > the ADC with at least 10bits and up to 22 bits of min-entropy for a 32 > bits value, we conservatively assume the min-entropy is 10 bits out of > 32 bits, so that's why set entropy quality to 320/1024 = 10/32. Also > we have explained in the commit message why can't use the HW RNG > framework. > > Otherwise, your patch will cause high CPU load, as continuously read > ADC data if entropy bits under write_wakeup_threshold. Please don't top post, it breaks patchwork which is extremely annoying for me: https://patchwork.kernel.org/patch/9266265/ https://patchwork.kernel.org/patch/9266617/ -- Kalle Valo