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=-4.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED autolearn=unavailable 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 BB823C04AB6 for ; Tue, 14 May 2019 18:16:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8FDFB20850 for ; Tue, 14 May 2019 18:16:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=googlemail.com header.i=@googlemail.com header.b="HHumoDlF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727556AbfENSQk (ORCPT ); Tue, 14 May 2019 14:16:40 -0400 Received: from mail-oi1-f196.google.com ([209.85.167.196]:39805 "EHLO mail-oi1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726348AbfENSQk (ORCPT ); Tue, 14 May 2019 14:16:40 -0400 Received: by mail-oi1-f196.google.com with SMTP id v2so9436483oie.6; Tue, 14 May 2019 11:16:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=4YMSOdywhMDkZIusrQTvSoGh0Q6ONeiUFTYpafArN1A=; b=HHumoDlFG8R5gAm3Ad1ciIosYI3vaJ7hvHU+HejRRC3yCLveG8A8/bU2GI1BTbzPaH IUwfrvrdpaTW6+rlhxdctqH0ds3IQeGLswlJygQJo8Wy8owPgytP15gmPLZgAk4FkBDg NgZhOKRTzusOhfrD0OLcPwc6cOCFj7fIZbmQX3qUu2d5lDU5d2QhslTTaVbc9IjZZG/C rARWXf1jUvtJLOMJCZ+Ly5WWspAoAMkEbPRS2xtQz0P3kLU+xBfNqPrhlzInuNT65nGC KMyOwwLqwZW5V3mdgjKe/Vi2o3InWL6SK1ZVnKOqmz9Smip2Y7WHvEvf+2+YD2o1F/Cm 8TRA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=4YMSOdywhMDkZIusrQTvSoGh0Q6ONeiUFTYpafArN1A=; b=C3UXHAwF3AXmNoefDJKL+/SyhC38nb0fdHxQjxI7/5YO/omGeNckktqJeXLDM77+CJ 3zjXG9omGPutDj2GaF1uWQgTXilRzSidakNTSpndKBL1pjhv4JIjRaMoUSio0Mnm8u7D TDEtsyN4Q//JQoDlsu0R+sicVUrsgUZjbKykO4RUhbgEhp+KX96hsryX7g46uY0XfJmz LN+hy91JYEqqYD4MucQbQyHxnP5D7NqHypaPXC3JfQiW7QpeQggS/nb3t43SsHVChb0p AQToTGJxQAfoMpdngWyuEjzTu/eGmVcM/KqJ7v7pEq+dJo/u9PFGa2cCuHDirk8+rfZi 8ZzA== X-Gm-Message-State: APjAAAWvSN8ScZsQb3HMM39718PgX+ytBcBOPrPxYCQLpPoqXgGZ9lc9 zC94eo+ZC4s5mbjbmYYNBqzU68brY6Mgw6I0GUU= X-Google-Smtp-Source: APXvYqyY2t4CYQPKEHqtsUwWM2Rw8XRLaW0voMCaWNP5OK2WwOoKu/4mjsM6cQLFKNXGKuBZGFlXDA3GnbdV2cYN/5E= X-Received: by 2002:aca:b68a:: with SMTP id g132mr3805890oif.47.1557857799214; Tue, 14 May 2019 11:16:39 -0700 (PDT) MIME-Version: 1.0 References: <20190513123115.18145-1-jbrunet@baylibre.com> <20190513123115.18145-2-jbrunet@baylibre.com> In-Reply-To: <20190513123115.18145-2-jbrunet@baylibre.com> From: Martin Blumenstingl Date: Tue, 14 May 2019 20:16:28 +0200 Message-ID: Subject: Re: [PATCH v2 1/7] clk: meson: mpll: properly handle spread spectrum To: Jerome Brunet Cc: Neil Armstrong , Michael Turquette , Stephen Boyd , Kevin Hilman , linux-amlogic@lists.infradead.org, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 13, 2019 at 2:31 PM Jerome Brunet wrote: > > The bit 'SSEN' available on some MPLL DSS outputs is not related to the > fractional part of the divider but to the function called > 'Spread Spectrum'. > > This function might be used to solve EM issues by adding a jitter on > clock signal. This widens the signal spectrum and weakens the peaks in it. > > While spread spectrum might be useful for some application, it is > problematic for others, such as audio. > > This patch introduce a new flag to the MPLL driver to enable (or not) the > spread spectrum function. > > Fixes: 1f737ffa13ef ("clk: meson: mpll: fix mpll0 fractional part ignored") > Signed-off-by: Jerome Brunet in v1 [0] I checked that Ethernet is still working on my Odroid-C1. I didn't repeat this test with v2 but since the logic has not changed you can still add my: Tested-by: Martin Blumenstingl [0] https://patchwork.kernel.org/patch/10877431/