From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-x244.google.com (mail-pf0-x244.google.com [IPv6:2607:f8b0:400e:c00::244]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 40K9PR4trNzDqyW for ; Mon, 9 Apr 2018 09:58:35 +1000 (AEST) Received: by mail-pf0-x244.google.com with SMTP id y66so4706455pfi.7 for ; Sun, 08 Apr 2018 16:58:35 -0700 (PDT) From: Nicolin Chen To: broonie@kernel.org, marex@denx.de 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 Subject: [PATCH] ASoC: fsl_esai: Fix divisor calculation failure at lower ratio Date: Sun, 8 Apr 2018 16:57:35 -0700 Message-Id: <1523231855-7854-1-git-send-email-nicoleotsuka@gmail.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 --- 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; -- 2.7.4