From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751264AbdEaO6l (ORCPT ); Wed, 31 May 2017 10:58:41 -0400 Received: from mout.kundenserver.de ([212.227.126.133]:65174 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751032AbdEaO6j (ORCPT ); Wed, 31 May 2017 10:58:39 -0400 Subject: Re: [PATCH v2 0/2] clk: bcm2835: PCM clock improvements To: Phil Elwell , Michael Turquette , Stephen Boyd , Eric Anholt , Florian Fainelli , linux-clk@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <4c11ad43-ef4e-3fbd-500a-02b2b46e0fbd@raspberrypi.org> From: Stefan Wahren Message-ID: Date: Wed, 31 May 2017 16:58:01 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: de-DE X-Provags-ID: V03:K0:iwkTJLUNT/6E1K7VOWiL/YzSy1QzFCcXIS/LSIZ/6cZhvv+lyAk YbX9+ZfsjCoaERBex3HW04jnkuH1COUD9qsGtF4QQCZ+yuEocs2MuioELt9RLkyRMfSrYBM u7qtFBaP4uk1jgbZeKT8qZTN7IHIqALPxpdQTtE+G+o5uK6i8XsP3Qfvy5hMXuK5WP8WIH4 K5ayArAAs4pbzdeVWygYA== X-UI-Out-Filterresults: notjunk:1;V01:K0:Va2IqUH7UUA=:0mZFN+o5sj5lr1epDuVKhp NN/XE4FJKMgqrFawLwcT25hLjgB5CpQ7B6n8ye4UUPb/d6wKwIuBxaamo2ShsnDDvMA6GfpLK TsW7J7Qz8vFQUjhFSXVcvq3vzv5y4DqmeEmbwfofl/nTrLB41AKtERtJdnigy8M7wGMcSpE9i GmRGLIYZX9U1vWvyGcZRVgagyRKh6jvMIqFe6ILs5YkdbKEKRlvIIkxdocVa3lgVbm/uRdGGt a1C7uMYXlEMg+18hzmQ192j34KBeUGIt35xUOJ1Vq0tW38MwSYYkLtB7+kb40h1SiFDqOCivK G1RC8kcdPGpIy+5NJvrFmy6eNPk1/HwZAR5y4y7mY6JKjNCgHo2/Ald8DXI3E7vUfszo7UZCQ TVGM6ai8mBDoD7zIcdeLUHC08LGJrdoO7XI1nZiXjoXH0G4gMWnky1ihmqRr/O1yTFPLq7eob ZIbus7qFp5DfbeQw9D1lkj+aBYhjABhWwgvzm/qzAbvCT2Dg3+xBreEUec/XxZUcSPTausPZ/ s4NjpQPo/oUedQQLVbYd5aKuZCYu5+Pfd4n9kM0VI8hOjSbYt1+FZq80W3fySJnoB+1g7c/w8 UCCbU1Z/xCkTfx+nxGdMUHhpu0DPUyICUQgeTT94+BG1o+A/cM2ByyiD9Lq0h0SM6upOGdbSp nDfgpegScwkn8HJOp1WQDe2mW29tTF2nzZF5qvB5wctPiG4W6eUdeHhE5w5+0O5zpr2IbX/mc rbas05L1wwkebmcX Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 31.05.2017 um 11:18 schrieb Phil Elwell: > The switch to using the upstream bcm2835_cprman clock driver caused a > few problems for users of PCM (I2S) peripherals. Audio applications > require accurate, stable clocks, and the cprman driver wasn't > conservative enough in its choice of clock sources. > > These patches restrict the clock sources for the PCM peripheral in two > ways: the first causes all possible sources except OSC and PLLD_PER > to be ignored, while the second allows clocks to be specified as > "low_jitter", causing the effects of fractional divisors to be taken > into account when comparing potential clocks for accuracy. In practice, > the combined effect of the two patches is to choose OSC as a source if > an integer divisor can be used, otherwise PLLD_PER is chosen. > > Changes in v2: > * Extended bcm2835_pcm_per_parents to cover the pllh_aux slot, and gave > it a comment in patch 1. > * Added a REGISTER_PCM_CLK analagous to REGISTER_PER_CLK in patch 1. > * Renamed temporary variable idiv to int_div in patch 2. > > Phil Elwell (2): > clk: bcm2835: Limit PCM clock to OSC and PLLD_PER > clk: bcm2835: Minimise clock jitter for PCM clock > > drivers/clk/bcm/clk-bcm2835.c | 50 ++++++++++++++++++++++++++++++++++++++----- > 1 file changed, 45 insertions(+), 5 deletions(-) > For the whole series: Acked-by: Stefan Wahren I hope Eric as the author of the driver has a chance to look over the patches. Stefan