linux-kernel - Re: [PATCH 1/3] ASoC: simple-card-utils: Fix device module clock

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Date:   12 Feb 2021 08:44:43 +0900
From:   Kuninori Morimoto <kuninori.morimoto.gx@...esas.com>
To:     Sameer Pujar <spujar@...dia.com>
Cc:     <broonie@...nel.org>, <robh@...nel.org>,
        <thierry.reding@...il.com>, <jonathanh@...dia.com>,
        <alsa-devel@...a-project.org>, <devicetree@...r.kernel.org>,
        <linux-tegra@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <sharadg@...dia.com>
Subject: Re: [PATCH 1/3] ASoC: simple-card-utils: Fix device module clock


Hi Sameer

> diff --git a/sound/soc/generic/simple-card-utils.c b/sound/soc/generic/simple-card-utils.c
> index bc0b62e..0754d70 100644
> --- a/sound/soc/generic/simple-card-utils.c
> +++ b/sound/soc/generic/simple-card-utils.c
> @@ -173,16 +173,15 @@ int asoc_simple_parse_clk(struct device *dev,
>  	 *  or device's module clock.
>  	 */
>  	clk = devm_get_clk_from_child(dev, node, NULL);
> -	if (!IS_ERR(clk)) {
> -		simple_dai->sysclk = clk_get_rate(clk);
> +	if (IS_ERR(clk))
> +		clk = devm_get_clk_from_child(dev, dlc->of_node, NULL);
>  
> +	if (!IS_ERR(clk)) {
>  		simple_dai->clk = clk;
> -	} else if (!of_property_read_u32(node, "system-clock-frequency", &val)) {
> +		simple_dai->sysclk = clk_get_rate(clk);
> +	} else if (!of_property_read_u32(node, "system-clock-frequency",
> +					 &val)) {
>  		simple_dai->sysclk = val;
> -	} else {
> -		clk = devm_get_clk_from_child(dev, dlc->of_node, NULL);
> -		if (!IS_ERR(clk))
> -			simple_dai->sysclk = clk_get_rate(clk);
>  	}

The comment is indicating that that the clock parsing order,
but this patch exchanges it.
This comment also should be updated, I think.

	/*
	 * Parse dai->sysclk come from "clocks = <&xxx>"
	 * (if system has common clock)
	 *  or "system-clock-frequency = <xxx>"
	 *  or device's module clock.
	 */

asoc_simple_set_clk_rate() will be called if it has simple_dai->clk.
CPU or Codec component clock rate will be exchanged by this patch, I think.
I'm not sure the effect of this patch to existing boards.

And also, this patch has too many unneeded exchange,
thus it was difficult to read for me.
I think it can be simply like this ?
It is understandable what it want to do.

diff --git a/sound/soc/generic/simple-card-utils.c b/sound/soc/generic/simple-card-utils.c
index 8c423afb9d2e..d441890de4dc 100644
--- a/sound/soc/generic/simple-card-utils.c
+++ b/sound/soc/generic/simple-card-utils.c
@@ -168,16 +168,14 @@ int asoc_simple_parse_clk(struct device *dev,
 	 *  or device's module clock.
 	 */
 	clk = devm_get_clk_from_child(dev, node, NULL);
+	if (IS_ERR(clk))
+		clk = devm_get_clk_from_child(dev, dlc->of_node, NULL);
+
 	if (!IS_ERR(clk)) {
 		simple_dai->sysclk = clk_get_rate(clk);
-
 		simple_dai->clk = clk;
 	} else if (!of_property_read_u32(node, "system-clock-frequency", &val)) {
 		simple_dai->sysclk = val;
-	} else {
-		clk = devm_get_clk_from_child(dev, dlc->of_node, NULL);
-		if (!IS_ERR(clk))
-			simple_dai->sysclk = clk_get_rate(clk);
 	}
 
 	if (of_property_read_bool(node, "system-clock-direction-out"))




Thank you for your help !!

Best regards
---
Kuninori Morimoto