Re: [PATCH v3] ASoC: simple-card-utils: add sysclk ordering support

[Kuninori Morimoto]

Hi Stefano

Thank you for your patch

> When simple-audio-card programs sysclk for CPU and codec DAIs during
> hw_params, the ordering of these calls may matter on some platforms.
> 
> Some CPU DAIs finalize or adjust the MCLK rate as part of their
> set_sysclk() callback (for example by calling clk_set_rate()). If the
> codec sysclk is configured before the CPU DAI applies the final MCLK
> rate, the codec may configure its internal clocking based on a
> non-final MCLK value.
> 
> Such situations can arise depending on the clock provider/consumer
> relationship between the CPU DAI and the codec.
> 
> Introduce an explicit sysclk ordering enum in simple-card-utils and use
> it to control the order of snd_soc_dai_set_sysclk() calls in the mclk-fs
> handling path. The default behaviour remains unchanged (codec-first)
> to avoid regressions.
> 
> Signed-off-by: Stefano Radaelli <stefano.r@xxxxxxxxxxxxx>
> ---
(snip)
> +enum simple_util_sysclk_order {
> +	SIMPLE_SYSCLK_ORDER_UNSPEC = 0,
> +	SIMPLE_SYSCLK_ORDER_CODEC_FIRST,
> +	SIMPLE_SYSCLK_ORDER_CPU_FIRST,
> +};

I think UNSPEC is not needed ?

	enum simple_util_sysclk_order {
		SIMPLE_SYSCLK_ORDER_CODEC_FIRST = 0,
		SIMPLE_SYSCLK_ORDER_CPU_FIRST,
	};

Do you set this "order" via custome driver if you want ot use CPU_FIRST ?

Thank you for your help !!

Best regards
---
Kuninori Morimoto