From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH] clk: tegra: PLLE spread spectrum control Date: Thu, 03 Oct 2013 09:23:55 -0600 Message-ID: <524D8C0B.90707@wwwdotorg.org> References: <1380209654-25458-1-git-send-email-pdeschrijver@nvidia.com> <524B28EA.40702@wwwdotorg.org> <20131003105228.GK3973@tbergstrom-lnx.Nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20131003105228.GK3973-Rysk9IDjsxmJz7etNGeUX8VPkgjIgRvpAL8bYrjMMd8@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Peter De Schrijver Cc: Mike Turquette , Prashant Gaikwad , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On 10/03/2013 04:52 AM, Peter De Schrijver wrote: > On Tue, Oct 01, 2013 at 09:56:26PM +0200, Stephen Warren wrote: >> On 09/26/2013 09:34 AM, Peter De Schrijver wrote: >>> Add spread spectrum control for PLLE in Tegra114. >> >> It would be useful to have some description of the end-user-visible >> benefit of this change; why is it useful? > > spread spectrum clocking is a technique to reduce EMI caused by the clock > signal by modulating the frequency with a low frequency signal. This should > reduce interference with eg. Wifi or cellular modems on the same board. Great. The intent of my request was for that information to be included in the patch description. From mboxrd@z Thu Jan 1 00:00:00 1970 From: swarren@wwwdotorg.org (Stephen Warren) Date: Thu, 03 Oct 2013 09:23:55 -0600 Subject: [PATCH] clk: tegra: PLLE spread spectrum control In-Reply-To: <20131003105228.GK3973@tbergstrom-lnx.Nvidia.com> References: <1380209654-25458-1-git-send-email-pdeschrijver@nvidia.com> <524B28EA.40702@wwwdotorg.org> <20131003105228.GK3973@tbergstrom-lnx.Nvidia.com> Message-ID: <524D8C0B.90707@wwwdotorg.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 10/03/2013 04:52 AM, Peter De Schrijver wrote: > On Tue, Oct 01, 2013 at 09:56:26PM +0200, Stephen Warren wrote: >> On 09/26/2013 09:34 AM, Peter De Schrijver wrote: >>> Add spread spectrum control for PLLE in Tegra114. >> >> It would be useful to have some description of the end-user-visible >> benefit of this change; why is it useful? > > spread spectrum clocking is a technique to reduce EMI caused by the clock > signal by modulating the frequency with a low frequency signal. This should > reduce interference with eg. Wifi or cellular modems on the same board. Great. The intent of my request was for that information to be included in the patch description. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754275Ab3JCPYD (ORCPT ); Thu, 3 Oct 2013 11:24:03 -0400 Received: from avon.wwwdotorg.org ([70.85.31.133]:47031 "EHLO avon.wwwdotorg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753648Ab3JCPYB (ORCPT ); Thu, 3 Oct 2013 11:24:01 -0400 Message-ID: <524D8C0B.90707@wwwdotorg.org> Date: Thu, 03 Oct 2013 09:23:55 -0600 From: Stephen Warren User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.0 MIME-Version: 1.0 To: Peter De Schrijver CC: Mike Turquette , Prashant Gaikwad , "linux-arm-kernel@lists.infradead.org" , "linux-tegra@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] clk: tegra: PLLE spread spectrum control References: <1380209654-25458-1-git-send-email-pdeschrijver@nvidia.com> <524B28EA.40702@wwwdotorg.org> <20131003105228.GK3973@tbergstrom-lnx.Nvidia.com> In-Reply-To: <20131003105228.GK3973@tbergstrom-lnx.Nvidia.com> X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/03/2013 04:52 AM, Peter De Schrijver wrote: > On Tue, Oct 01, 2013 at 09:56:26PM +0200, Stephen Warren wrote: >> On 09/26/2013 09:34 AM, Peter De Schrijver wrote: >>> Add spread spectrum control for PLLE in Tegra114. >> >> It would be useful to have some description of the end-user-visible >> benefit of this change; why is it useful? > > spread spectrum clocking is a technique to reduce EMI caused by the clock > signal by modulating the frequency with a low frequency signal. This should > reduce interference with eg. Wifi or cellular modems on the same board. Great. The intent of my request was for that information to be included in the patch description.