From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752076AbeDIXqE (ORCPT ); Mon, 9 Apr 2018 19:46:04 -0400 Received: from mail-out.m-online.net ([212.18.0.10]:36731 "EHLO mail-out.m-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751663AbeDIXqC (ORCPT ); Mon, 9 Apr 2018 19:46:02 -0400 X-Auth-Info: yv5Gx+ytTmD/8AZzlzOnGc2RBlILjm/VrNh/abD/A0c= Subject: Re: [PATCH] ASoC: fsl_esai: Fix divisor calculation failure at lower ratio To: Nicolin Chen , broonie@kernel.org Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, alsa-devel@alsa-project.org, tiwai@suse.com, perex@perex.cz, lgirdwood@gmail.com, fabio.estevam@nxp.com References: <1523231855-7854-1-git-send-email-nicoleotsuka@gmail.com> From: Marek Vasut Message-ID: <42010284-6fbd-2d1a-ffe1-8a825478d1d7@denx.de> Date: Mon, 9 Apr 2018 23:43:02 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <1523231855-7854-1-git-send-email-nicoleotsuka@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/09/2018 01:57 AM, Nicolin Chen wrote: > When the desired ratio is less than 256, the savesub (tolerance) > in the calculation would become 0. This will then fail the loop- > search immediately without reporting any errors. > > But if the ratio is smaller enough, there is no need to calculate > the tolerance because PM divisor alone is enough to get the ratio. > > So a simple fix could be just to set PM directly instead of going > into the loop-search. > > Reported-by: Marek Vasut > Signed-off-by: Nicolin Chen > Cc: Marek Vasut On i.MX6Q with TI PCM1808 Tested-by: Marek Vasut > --- > sound/soc/fsl/fsl_esai.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/sound/soc/fsl/fsl_esai.c b/sound/soc/fsl/fsl_esai.c > index 40a7004..da8fd98 100644 > --- a/sound/soc/fsl/fsl_esai.c > +++ b/sound/soc/fsl/fsl_esai.c > @@ -144,6 +144,13 @@ static int fsl_esai_divisor_cal(struct snd_soc_dai *dai, bool tx, u32 ratio, > > psr = ratio <= 256 * maxfp ? ESAI_xCCR_xPSR_BYPASS : ESAI_xCCR_xPSR_DIV8; > > + /* Do not loop-search if PM (1 ~ 256) alone can serve the ratio */ > + if (ratio <= 256) { > + pm = ratio; > + fp = 1; > + goto out; > + } > + > /* Set the max fluctuation -- 0.1% of the max devisor */ > savesub = (psr ? 1 : 8) * 256 * maxfp / 1000; > > -- Best regards, Marek Vasut