linux-kernel - Re: [PATCH RESEND 2/4] ASoC: wm8962: Don't disable SYSCLK if it's enabled via DAPM

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Message-ID: <aV0ck+O4ysmA25s6@opensource.cirrus.com>
Date: Tue, 6 Jan 2026 14:30:43 +0000
From: Charles Keepax <ckeepax@...nsource.cirrus.com>
To: sebastian.krzyszkowiak@...i.sm
Cc: Liam Girdwood <lgirdwood@...il.com>, Mark Brown <broonie@...nel.org>,
        Jaroslav Kysela <perex@...ex.cz>, Takashi Iwai <tiwai@...e.com>,
        patches@...nsource.cirrus.com, linux-sound@...r.kernel.org,
        linux-kernel@...r.kernel.org, kernel@...i.sm
Subject: Re: [PATCH RESEND 2/4] ASoC: wm8962: Don't disable SYSCLK if it's
 enabled via DAPM

On Mon, Jan 05, 2026 at 04:02:09AM +0100, Sebastian Krzyszkowiak via B4 Relay wrote:
> From: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@...i.sm>
> 
> If SYSCLK pin is enabled via DAPM, wm8962_configure_bclk may turn it off
> behind DAPM's back, making it assume that the clock is still enabled even
> if it actually isn't, which can end up with it not being enabled for
> playback or capture when it's needed.
> 
> Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@...i.sm>
> ---
>  sound/soc/codecs/wm8962.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/sound/soc/codecs/wm8962.c b/sound/soc/codecs/wm8962.c
> index 1040740fc80f..843b8c6b40a4 100644
> --- a/sound/soc/codecs/wm8962.c
> +++ b/sound/soc/codecs/wm8962.c
> @@ -2520,7 +2520,8 @@ static void wm8962_configure_bclk(struct snd_soc_component *component)
>  	usleep_range(500, 1000);
>  	dspclk = snd_soc_component_read(component, WM8962_CLOCKING1);
>  
> -	if (snd_soc_dapm_get_bias_level(dapm) != SND_SOC_BIAS_ON)
> +	if (snd_soc_dapm_get_bias_level(dapm) != SND_SOC_BIAS_ON
> +	    && !snd_soc_dapm_get_pin_status(dapm, "SYSCLK"))

Something seems a little weird here. I guess SYSCLK is a supply
widget, so it can technically be on before the card bias level is
fully on. But SYSCLK usually supplies other widgets that would
require the bias to be fully on, so what causes it to be on? Or
is this a transitional state as things are powering up?

Thanks,
Charles