From: Stefano Radaelli <stefano.r@variscite.com>

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@variscite.com>
---
v4:
 - Removed SIMPLE_SYSCLK_ORDER_UNSPEC enum

v3:
 - DT flag not applicable, not a hardware configuration
 - Introduced enum to support order configuration
Link: https://patchwork.kernel.org/project/alsa-devel/patch/20260211112815.126734-1-stefano.r@variscite.com/

v2:
 - Do not change the default sysclk ordering
 - Make the ordering selectable via DT flag
 - Add DT binding documentation
Link: https://patchwork.kernel.org/project/alsa-devel/patch/20260210164506.161810-2-stefano.r@variscite.com/

v1:
 - Changed sysclk order, cpu first, then codec
Link: https://patchwork.kernel.org/project/alsa-devel/patch/20260206134014.143057-1-stefano.r@variscite.com/

 include/sound/simple_card_utils.h     |  6 ++++
 sound/soc/generic/simple-card-utils.c | 41 ++++++++++++++++++++-------
 2 files changed, 36 insertions(+), 11 deletions(-)

diff --git a/include/sound/simple_card_utils.h b/include/sound/simple_card_utils.h
index 69a9c9c4d0e9..915e6ae5f68d 100644
--- a/include/sound/simple_card_utils.h
+++ b/include/sound/simple_card_utils.h
@@ -54,6 +54,11 @@ struct prop_nums {
 	int platforms;
 };
 
+enum simple_util_sysclk_order {
+	SIMPLE_SYSCLK_ORDER_CODEC_FIRST = 0,
+	SIMPLE_SYSCLK_ORDER_CPU_FIRST,
+};
+
 struct simple_util_priv {
 	struct snd_soc_card snd_card;
 	struct simple_dai_props {
@@ -63,6 +68,7 @@ struct simple_util_priv {
 		struct snd_soc_codec_conf *codec_conf;
 		struct prop_nums num;
 		unsigned int mclk_fs;
+		enum simple_util_sysclk_order sysclk_order;
 	} *dai_props;
 	struct simple_util_jack hp_jack;
 	struct simple_util_jack mic_jack;
diff --git a/sound/soc/generic/simple-card-utils.c b/sound/soc/generic/simple-card-utils.c
index bdc02e85b089..fdd8b76f2914 100644
--- a/sound/soc/generic/simple-card-utils.c
+++ b/sound/soc/generic/simple-card-utils.c
@@ -468,6 +468,7 @@ int simple_util_hw_params(struct snd_pcm_substream *substream,
 	struct snd_soc_dai *sdai;
 	struct simple_util_priv *priv = snd_soc_card_get_drvdata(rtd->card);
 	struct simple_dai_props *props = runtime_simple_priv_to_props(priv, rtd);
+	enum simple_util_sysclk_order order = props->sysclk_order;
 	unsigned int mclk, mclk_fs = 0;
 	int i, ret;
 
@@ -501,18 +502,36 @@ int simple_util_hw_params(struct snd_pcm_substream *substream,
 				goto end;
 		}
 
-		for_each_rtd_codec_dais(rtd, i, sdai) {
-			pdai = simple_props_to_dai_codec(props, i);
-			ret = snd_soc_dai_set_sysclk(sdai, 0, mclk, pdai->clk_direction);
-			if (ret && ret != -ENOTSUPP)
-				goto end;
-		}
+		if (order == SIMPLE_SYSCLK_ORDER_CPU_FIRST) {
+			/* CPU first */
+			for_each_rtd_cpu_dais(rtd, i, sdai) {
+				pdai = simple_props_to_dai_cpu(props, i);
+				ret = snd_soc_dai_set_sysclk(sdai, 0, mclk, pdai->clk_direction);
+				if (ret && ret != -ENOTSUPP)
+					goto end;
+			}
 
-		for_each_rtd_cpu_dais(rtd, i, sdai) {
-			pdai = simple_props_to_dai_cpu(props, i);
-			ret = snd_soc_dai_set_sysclk(sdai, 0, mclk, pdai->clk_direction);
-			if (ret && ret != -ENOTSUPP)
-				goto end;
+			for_each_rtd_codec_dais(rtd, i, sdai) {
+				pdai = simple_props_to_dai_codec(props, i);
+				ret = snd_soc_dai_set_sysclk(sdai, 0, mclk, pdai->clk_direction);
+				if (ret && ret != -ENOTSUPP)
+					goto end;
+			}
+		} else {
+			/* default: codec first */
+			for_each_rtd_codec_dais(rtd, i, sdai) {
+				pdai = simple_props_to_dai_codec(props, i);
+				ret = snd_soc_dai_set_sysclk(sdai, 0, mclk, pdai->clk_direction);
+				if (ret && ret != -ENOTSUPP)
+					goto end;
+			}
+
+			for_each_rtd_cpu_dais(rtd, i, sdai) {
+				pdai = simple_props_to_dai_cpu(props, i);
+				ret = snd_soc_dai_set_sysclk(sdai, 0, mclk, pdai->clk_direction);
+				if (ret && ret != -ENOTSUPP)
+					goto end;
+			}
 		}
 	}
 

base-commit: b7ff7151e653aa296ab6c5495b2c1ab7c21eb250
-- 
2.47.3

On Fri, 13 Feb 2026 16:03:55 +0100, Stefano Radaelli wrote:
> 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.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/1] ASoC: simple-card-utils: add sysclk ordering support
      commit: d075cef4af6327a5de4bee7bf77591e3201e54f4

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

Hi Stefano

> From: Stefano Radaelli <stefano.r@variscite.com>
> 
> 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@variscite.com>
> ---

Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>

Thank you for your help !!

Best regards
---
Kuninori Morimoto