From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755913AbbGUVQe (ORCPT ); Tue, 21 Jul 2015 17:16:34 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:34201 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754804AbbGUVQc (ORCPT ); Tue, 21 Jul 2015 17:16:32 -0400 Message-ID: <55AEB6AE.2070006@codeaurora.org> Date: Tue, 21 Jul 2015 14:16:30 -0700 From: Stephen Boyd User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130329 Thunderbird/17.0.5 MIME-Version: 1.0 To: Douglas Anderson CC: Heiko Stuebner , linux-rockchip@lists.infradead.org, ykk@rock-chips.com, Alexandru Stan , mturquette@baylibre.com, linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] clk: rockchip: Fix PLL bandwidth References: <1437511283-14216-1-git-send-email-dianders@chromium.org> In-Reply-To: <1437511283-14216-1-git-send-email-dianders@chromium.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/21/2015 01:41 PM, Douglas Anderson wrote: > In the TRM we see that BWADJ is "a 12-bit bus that selects the values > 1-4096 for the bandwidth divider (NB)": > NB = BWADJ[11:0] + 1 > The recommended setting of NB: NB = NF / 2. > > So: > NB = NF / 2 > BWADJ[11:0] + 1 = NF / 2 > BWADJ[11:0] = NF / 2 - 1 > > Right now, we have: > > { \ > .rate = _rate##U, \ > .nr = _nr, \ > .nf = _nf, \ > .no = _no, \ > .bwadj = (_nf >> 1), \ > } > > That means we set bwadj to NF / 2, not NF / 2 - 1 > > All of this is a bit confusing because we specify "NR" (the 1-based > value), "NF" (the 1-based value), "NO" (the 1-based value), but > "BWADJ" (the 0-based value) instead of "NB" (the 1-based value). > > Let's change to working with "NB" and fix the off by one error. This > may affect PLL jitter in a small way (hopefully for the better). > > Signed-off-by: Douglas Anderson > There's no Fixes tag or stable Cc so I take it this isn't fixing any manifesting regression, more of a visual inspection bug find? -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project