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Date:   Sun, 7 Mar 2021 17:29:52 +0000
From:   Charles Keepax <ckeepax@opensource.cirrus.com>
To:     Shengjiu Wang <shengjiu.wang@nxp.com>
CC:     <lgirdwood@gmail.com>, <broonie@kernel.org>, <perex@perex.cz>,
        <tiwai@suse.com>, <kuninori.morimoto.gx@renesas.com>,
        <peter.ujfalusi@ti.com>, <gustavoars@kernel.org>,
        <pierre-louis.bossart@linux.intel.com>,
        <patches@opensource.cirrus.com>, <alsa-devel@alsa-project.org>,
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] ASoC: wm8962: Relax bit clock divider searching
Message-ID: <20210307172952.GG106851@ediswmail.ad.cirrus.com>
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On Wed, Mar 03, 2021 at 07:21:28PM +0800, Shengjiu Wang wrote:
> With S20_3LE format case, the sysclk = rate * 384,
> the bclk = rate * 20 * 2, there is no proper bclk divider
> for 384 / 40, because current condition needs exact match.
> So driver fails to configure the clocking:
> 
> wm8962 3-001a: Unsupported BCLK ratio 9
> 
> Fix this by relaxing bitclk divider searching, so that when
> no exact value can be derived from sysclk pick the closest
> value greater than expected bitclk.
> 
> Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> ---
>  sound/soc/codecs/wm8962.c | 21 +++++++++++----------
>  1 file changed, 11 insertions(+), 10 deletions(-)
> 
> diff --git a/sound/soc/codecs/wm8962.c b/sound/soc/codecs/wm8962.c
> index ce4666a74793..f5cd22450190 100644
> --- a/sound/soc/codecs/wm8962.c
> +++ b/sound/soc/codecs/wm8962.c
> @@ -2403,6 +2403,7 @@ static const int sysclk_rates[] = {
>  static void wm8962_configure_bclk(struct snd_soc_component *component)
>  {
>  	struct wm8962_priv *wm8962 = snd_soc_component_get_drvdata(component);
> +	int best, min_diff, diff;
>  	int dspclk, i;
>  	int clocking2 = 0;
>  	int clocking4 = 0;
> @@ -2473,23 +2474,23 @@ static void wm8962_configure_bclk(struct snd_soc_component *component)
>  
>  	dev_dbg(component->dev, "DSPCLK is %dHz, BCLK %d\n", dspclk, wm8962->bclk);
>  

Very minor nit but it would probably be nice to have some
equivalent debug statement that prints out the actual BCLK we end
up with. There are a couple of statements printing the requested
speed, but nothing that will output what the driver actually
applies after this change.

Otherwise I think the change looks good.

Thanks,
Charles