From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_HIGH autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2A5DAC433EF for ; Tue, 19 Jun 2018 04:06:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D7C522083A for ; Tue, 19 Jun 2018 04:06:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="xUX5cqVZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D7C522083A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755553AbeFSEGk (ORCPT ); Tue, 19 Jun 2018 00:06:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:37898 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750732AbeFSEGj (ORCPT ); Tue, 19 Jun 2018 00:06:39 -0400 Received: from localhost (unknown [106.200.222.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 30E7820693; Tue, 19 Jun 2018 04:06:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1529381198; bh=A7Cny9HzS5Z48ZxbgUFP8g+6OQmpN+1foCbQ1l+fPqk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=xUX5cqVZphpeA3RZnGsV7D8oQtKr0M9BjKDIET26WTC8/e1jgitNcbhLl1r40fsmy mBJLHv3pi9i/I6X/qs7x+9saNSf1SdWQQUgDNzumbtlRb0sFxLFAsyCr4sisS/kiEG A6bFkGIuc3y2/dUX6gANF/9pUo4bSYMbneC9s8Wo= Date: Tue, 19 Jun 2018 09:36:30 +0530 From: Vinod To: Stephen Boyd Cc: Bjorn Andersson , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, Matt Mackall , Herbert Xu , Arnd Bergmann , Greg Kroah-Hartman , linux-arm-msm@vger.kernel.org Subject: Re: [PATCH 3/3] hwrng: msm - Add support for prng v2 Message-ID: <20180619040630.GK25852@vkoul-mobl> References: <20180618141259.23141-1-vkoul@kernel.org> <20180618141259.23141-4-vkoul@kernel.org> <20180618182123.GT14924@minitux> <152935345439.16708.16472364970375601294@swboyd.mtv.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <152935345439.16708.16472364970375601294@swboyd.mtv.corp.google.com> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 18-06-18, 13:24, Stephen Boyd wrote: > Quoting Bjorn Andersson (2018-06-18 11:21:23) > > On Mon 18 Jun 07:12 PDT 2018, Vinod Koul wrote: > > > > > Qcom 8996 and later chips support prng v2 where we need to only > > > implement .read callback for hwrng. > > > > > > > The hardware still needs initialization, so I think you should expand > > this to mention that the initialization is moved to secure world and > > that's the reason why we only implement read. > > > > The question is what happens in projects with other security models. > > Can we still read the PRNG_CONFIG register to see if it's already been > configured or not and then bail out if it isn't configured? That would > be better as long as we the system doesn't blow up if non-secure mode > tries to read the config register. Unfortunately it did blow up for me when I tried it.. -- ~Vinod