Subject: Re: [PATCH] ASoC: rockchip: i2s-tdm: Use param rate if not provided by set_sysclk

From: Alexandre Belloni <[email-masked]>
Date: Thu, 19 Feb 2026 10:37:18 +0100

Hello,

On 18/02/2026 15:18:34-0500, Detlev Casanova wrote:
> Drivers will not always call set_sysclk() for all clocks, especially when
> default mclk-fs can be used.
> When that is the case, use the clock rate set in the params multiplied by the
> default mclk-fs.
> 
> Fixes: 5323186e2e8d ("ASoC: rockchip: i2s_tdm: Re-add the set_sysclk callback")
> Signed-off-by: Detlev Casanova <[email-masked]>
> ---
>  sound/soc/rockchip/rockchip_i2s_tdm.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/sound/soc/rockchip/rockchip_i2s_tdm.c b/sound/soc/rockchip/rockchip_i2s_tdm.c
> index 770b9bfbb384..fc52149ed6ae 100644
> --- a/sound/soc/rockchip/rockchip_i2s_tdm.c
> +++ b/sound/soc/rockchip/rockchip_i2s_tdm.c
> @@ -22,6 +22,7 @@
>  
>  #define DRV_NAME "rockchip-i2s-tdm"
>  
> +#define DEFAULT_MCLK_FS				256
>  #define CH_GRP_MAX				4  /* The max channel 8 / 2 */
>  #define MULTIPLEX_CH_MAX			10
>  
> @@ -665,6 +666,15 @@ static int rockchip_i2s_tdm_hw_params(struct snd_pcm_substream *substream,
>  			mclk_rate = i2s_tdm->mclk_rx_freq;
>  		}
>  
> +		/*
> +		 * When the dai/component driver doesn't need to set mclk-fs for a specific
> +		 * clock, it can skip the call to set_sysclk() for that clock.
> +		 * In that case, simply use the clock rate from the params and multiply it by
> +		 * the default mclk-fs value.
> +		 */
> +		if (!mclk_rate)
> +			mclk_rate = DEFAULT_MCLK_FS * params_rate(params);
> +

Maybe this could be set as the default value of i2s_tdm->mclk_rx_freq
and i2s_tdm->mclk_tx_freq in rockchip_i2s_tdm_probe instead of relying
on it being 0 and testing later on?

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com