From patchwork Thu Apr 21 13:04:14 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Fitzgerald X-Patchwork-Id: 8900351 Return-Path: X-Original-To: patchwork-alsa-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id BA56FBF29F for ; Thu, 21 Apr 2016 13:04:49 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 49F43201B4 for ; Thu, 21 Apr 2016 13:04:44 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) by mail.kernel.org (Postfix) with ESMTP id 18FC52010F for ; Thu, 21 Apr 2016 13:04:40 +0000 (UTC) Received: by alsa0.perex.cz (Postfix, from userid 1000) id 8D7E32668BA; Thu, 21 Apr 2016 15:04:37 +0200 (CEST) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,NO_DNS_FOR_FROM, RCVD_IN_DNSWL_NONE,UNPARSEABLE_RELAY autolearn=no version=3.3.1 Received: from alsa0.perex.cz (localhost [127.0.0.1]) by alsa0.perex.cz (Postfix) with ESMTP id 9E80726683D; Thu, 21 Apr 2016 15:04:29 +0200 (CEST) X-Original-To: alsa-devel@alsa-project.org Delivered-To: alsa-devel@alsa-project.org Received: by alsa0.perex.cz (Postfix, from userid 1000) id A2C85266847; Thu, 21 Apr 2016 15:04:28 +0200 (CEST) Received: from mx0a-001ae601.pphosted.com (mx0a-001ae601.pphosted.com [67.231.149.25]) by alsa0.perex.cz (Postfix) with ESMTP id 319BB2666BD for ; Thu, 21 Apr 2016 15:04:20 +0200 (CEST) Received: from pps.filterd (m0077473.ppops.net [127.0.0.1]) by mx0a-001ae601.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u3LD3wZD008992; Thu, 21 Apr 2016 08:04:17 -0500 Authentication-Results: ppops.net; spf=none smtp.mail=rf@opensource.wolfsonmicro.com Received: from mail1.cirrus.com (mail1.cirrus.com [141.131.3.20]) by mx0a-001ae601.pphosted.com with ESMTP id 22bjsyfs84-1; Thu, 21 Apr 2016 08:04:17 -0500 Received: from EX17.ad.cirrus.com (unknown [172.20.9.81]) by mail1.cirrus.com (Postfix) with ESMTP id 07ECC34076; Thu, 21 Apr 2016 08:05:07 -0500 (CDT) Received: from imbe.wolfsonmicro.main (172.20.9.178) by EX17.ad.cirrus.com (172.20.9.81) with Microsoft SMTP Server id 14.3.248.2; Thu, 21 Apr 2016 14:04:15 +0100 Received: from rf-debian.wolfsonmicro.main ([172.22.20.36]) by imbe.wolfsonmicro.main (8.14.4/8.14.4) with ESMTP id u3LD4EW4029591; Thu, 21 Apr 2016 14:04:14 +0100 From: Richard Fitzgerald To: Date: Thu, 21 Apr 2016 14:04:14 +0100 Message-ID: <1461243854-31765-1-git-send-email-rf@opensource.wolfsonmicro.com> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1603290000 definitions=main-1604210212 Cc: alsa-devel@alsa-project.org, patches@opensource.wolfsonmicro.com, linux-kernel@vger.kernel.org Subject: [alsa-devel] [PATCH] ASoC: arizona: Prefer lower FRATIO in pseudo-fractional mode X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org X-Virus-Scanned: ClamAV using ClamSMTP When setting up an FLL in pseudo-fractional mode it is preferred to use a lower FRATIO if possible to give a higher reference clock frequency. This patch swaps the two loops in arizona_calc_fratio() so that lower FRATIOs are tried first. The decrementing loop is also changed to start from init_ratio because the original settings might already give a fractional value for N.K Signed-off-by: Richard Fitzgerald --- sound/soc/codecs/arizona.c | 27 +++++++++++++++------------ 1 file changed, 15 insertions(+), 12 deletions(-) diff --git a/sound/soc/codecs/arizona.c b/sound/soc/codecs/arizona.c index 0cd27e0..d1e1127 100644 --- a/sound/soc/codecs/arizona.c +++ b/sound/soc/codecs/arizona.c @@ -2039,7 +2039,21 @@ static int arizona_calc_fratio(struct arizona_fll *fll, init_ratio, Fref, refdiv); while (div <= ARIZONA_FLL_MAX_REFDIV) { - for (ratio = init_ratio; ratio <= ARIZONA_FLL_MAX_FRATIO; + /* start from init_ratio because this may already give a + * fractional N.K + */ + for (ratio = init_ratio; ratio > 0; ratio--) { + if (target % (ratio * Fref)) { + cfg->refdiv = refdiv; + cfg->fratio = ratio - 1; + arizona_fll_dbg(fll, + "pseudo: found fref=%u refdiv=%d(%d) ratio=%d\n", + Fref, refdiv, div, ratio); + return ratio; + } + } + + for (ratio = init_ratio + 1; ratio <= ARIZONA_FLL_MAX_FRATIO; ratio++) { if ((ARIZONA_FLL_VCO_CORNER / 2) / (fll->vco_mult * ratio) < Fref) { @@ -2065,17 +2079,6 @@ static int arizona_calc_fratio(struct arizona_fll *fll, } } - for (ratio = init_ratio - 1; ratio > 0; ratio--) { - if (target % (ratio * Fref)) { - cfg->refdiv = refdiv; - cfg->fratio = ratio - 1; - arizona_fll_dbg(fll, - "pseudo: found fref=%u refdiv=%d(%d) ratio=%d\n", - Fref, refdiv, div, ratio); - return ratio; - } - } - div *= 2; Fref /= 2; refdiv++;