[PATCH 0/2] ASoC: meson: aiu: fix playback issue for 24-bit mode

[PATCH 0/2] ASoC: meson: aiu: fix playback issue for 24-bit mode

[Valerio Setti]

A patch series has recently been merged in c7852d2dcf66
("ASoC: meson: aiu: align I2S design to the AXG one") which unfortunately
introduces a bug in 24 bit mode playback which this new series resolves.

Among other things the previous series moved the content of what was once
called 'aiu_encoder_i2s_setup_desc' from 'aiu-encoder-i2s' to
'aiu-formatter-i2s'.
'aiu_encoder_i2s_setup_desc' was basically accomplishing two tasks:
- reset the i2s pipeline.
- configure number of channels and physical samples width.
Before being moved 'aiu_encoder_i2s_setup_desc' was called in the encoder
DAI 'hw_params()', whereas after the move it is called at trigger time
('aiu_encoder_i2s_trigger'->'gx_stream_start' -> 'gx_formatter_enable' ->
'aiu_formatter_i2s_prepare').

In parallel 'aiu-fifo-i2s' (DAI FE) already performs the very same reset
of the pipeline at trigger time in 'aiu_fifo_i2s_trigger' and then it
triggers the playback.

Since the DAI triggering order is the default one (FE before BE) this
means that the pipeline reset happens when the BE already did it and
started the playback. This cause the 24-bit playback mode to be
corrupted.

This series:
- re-orders operations so that 'aiu_formatter_i2s_prepare' is called after
  DAIs' prepare, but before triggering them.
- removes pipeline reset from 'aiu_formatter_i2s_prepare' because the
  very same operation is done by 'aiu-fifo-i2s' on trigger.

This series depends on c7852d2dcf66 ("ASoC: meson: aiu: align I2S design
to the AXG one") which exists in 'broonie/sound.git#for-7.3', but which
has not been mainlined yet.

Please apologize for the inconvenience.

Signed-off-by: Valerio Setti <vsetti@baylibre.com>
---
Valerio Setti (2):
      ASoC: meson: gx-formatter: prepare on attach
      ASoC: meson: aiu-formatter: remove pipeline reset from prepare

 sound/soc/meson/aiu-formatter-i2s.c |  9 ++++-----
 sound/soc/meson/gx-formatter.c      | 33 +++++++++++++++++++++++++--------
 2 files changed, 29 insertions(+), 13 deletions(-)
---
base-commit: bff7fad1010eea6f183fb110b54171cf8700ef8e
change-id: 20260702-fix-24-bit-i2s-playback-6444174c7cd7

Best regards,
--  
Valerio Setti <vsetti@baylibre.com>

[PATCH 1/2] ASoC: meson: gx-formatter: prepare on attach

[Valerio Setti]

Instead of calling the formatter driver prepare and enable at the same
time when 'gx_stream_start' is called (which happens at trigger time),
split the operation in 2: prepare is called when the widget is powered
up, whereas enable is kept on 'gx_stream_start'.

This resolves a problem related to i2s playback in 24-bit mode. Commit
c7852d2dcf66 ("ASoC: meson: aiu: align I2S design to the AXG one") moved
the content of what was once called 'aiu_encoder_i2s_setup_desc' from
'aiu-encoder-i2s' to 'aiu-formatter-i2s'.

'aiu_encoder_i2s_setup_desc' was basically accomplishing two tasks:
- reset the i2s pipeline.
- configure number of channels and physical samples width.
Before being moved 'aiu_encoder_i2s_setup_desc' was called in the encoder
DAI 'hw_params()', whereas after the move it is called at trigger time
('aiu_encoder_i2s_trigger'->'gx_stream_start' -> 'gx_formatter_enable' ->
'aiu_formatter_i2s_prepare').

In parallel 'aiu-fifo-i2s' (DAI FE) already performs the very same reset
of the pipeline at trigger time in 'aiu_fifo_i2s_trigger' and then it
triggers the playback.

Since the DAI triggering order is the default one (FE before BE) this
means that the pipeline reset happens when the BE already did it and
started the playback. This cause the 24-bit playback mode to be
corrupted.

This commit re-orders operations so that 'aiu_formatter_i2s_prepare' is
called after DAIs' prepare, but before triggering them.

Signed-off-by: Valerio Setti <vsetti@baylibre.com>
---
 sound/soc/meson/gx-formatter.c | 33 +++++++++++++++++++++++++--------
 1 file changed, 25 insertions(+), 8 deletions(-)

diff --git a/sound/soc/meson/gx-formatter.c b/sound/soc/meson/gx-formatter.c
index 311e63affb23..c7333f624b15 100644
--- a/sound/soc/meson/gx-formatter.c
+++ b/sound/soc/meson/gx-formatter.c
@@ -15,27 +15,38 @@ struct gx_formatter {
 	struct gx_stream *stream;
 	const struct gx_formatter_driver *drv;
 	bool enabled;
+	bool prepared;
 	struct regmap *map;
 };
 
-static int gx_formatter_enable(struct gx_formatter *formatter)
+static int gx_formatter_prepare(struct gx_formatter *formatter)
 {
 	int ret;
 
-	/* Do nothing if the formatter is already enabled */
-	if (formatter->enabled)
+	if (formatter->prepared)
 		return 0;
 
 	/* Setup the stream parameter in the formatter */
 	if (formatter->drv->ops->prepare) {
 		ret = formatter->drv->ops->prepare(formatter->map,
-					   formatter->drv->quirks,
-					   formatter->stream);
+						   formatter->drv->quirks,
+						   formatter->stream);
 		if (ret)
 			return ret;
 	}
 
-	/* Finally, actually enable the formatter */
+	formatter->prepared = true;
+
+	return 0;
+}
+
+static int gx_formatter_enable(struct gx_formatter *formatter)
+{
+	/* Do nothing if the formatter is already enabled */
+	if (formatter->enabled)
+		return 0;
+
+	/* Enable the formatter */
 	if (formatter->drv->ops->enable)
 		formatter->drv->ops->enable(formatter->map);
 
@@ -63,6 +74,12 @@ static int gx_formatter_attach(struct gx_formatter *formatter)
 
 	mutex_lock(&ts->lock);
 
+	ret = gx_formatter_prepare(formatter);
+	if (ret) {
+		pr_err("failed to prepare the formatter\n");
+		goto out;
+	}
+
 	/* Catch up if the stream is already running when we attach */
 	if (ts->ready) {
 		ret = gx_formatter_enable(formatter);
@@ -87,9 +104,9 @@ static void gx_formatter_detach(struct gx_formatter *formatter)
 
 	mutex_lock(&ts->lock);
 	list_del(&formatter->list);
-	mutex_unlock(&ts->lock);
-
 	gx_formatter_disable(formatter);
+	formatter->prepared = false;
+	mutex_unlock(&ts->lock);
 }
 
 static int gx_formatter_power_up(struct gx_formatter *formatter,

-- 
2.47.3

[PATCH 2/2] ASoC: meson: aiu-formatter: remove pipeline reset from prepare

[Valerio Setti]

'aiu-formatter-i2s' already performs the very same reset in
'aiu_fifo_i2s_trigger' for all relevant trigger scenarios. There is no
need to duplicate the operation in the formatter.

Signed-off-by: Valerio Setti <vsetti@baylibre.com>
---
 sound/soc/meson/aiu-formatter-i2s.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/sound/soc/meson/aiu-formatter-i2s.c b/sound/soc/meson/aiu-formatter-i2s.c
index b4604734fe88..cb554c2e7ce4 100644
--- a/sound/soc/meson/aiu-formatter-i2s.c
+++ b/sound/soc/meson/aiu-formatter-i2s.c
@@ -13,7 +13,6 @@
 #define AIU_I2S_SOURCE_DESC_MODE_8CH	BIT(0)
 #define AIU_I2S_SOURCE_DESC_MODE_24BIT	BIT(5)
 #define AIU_I2S_SOURCE_DESC_MODE_32BIT	BIT(9)
-#define AIU_RST_SOFT_I2S_FAST		BIT(0)
 
 #define AIU_I2S_DAC_CFG_MSB_FIRST	BIT(2)
 
@@ -55,11 +54,11 @@ static int aiu_formatter_i2s_prepare(struct regmap *map,
 {
 	/* Always operate in split (classic interleaved) mode */
 	unsigned int desc = 0;
-	unsigned int tmp;
 
-	/* Reset required to update the pipeline */
-	regmap_write(map, AIU_RST_SOFT, AIU_RST_SOFT_I2S_FAST);
-	regmap_read(map, AIU_I2S_SYNC, &tmp);
+	/*
+	 * Pipeline reset is already implemented in aiu_fifo_i2s_trigger() at
+	 * trigger time.
+	 */
 
 	switch (ts->physical_width) {
 	case 16: /* Nothing to do */

-- 
2.47.3

Re: [PATCH 2/2] ASoC: meson: aiu-formatter: remove pipeline reset from prepare

[Jerome Brunet]

On jeu. 02 juil. 2026 at 12:56, Valerio Setti <vsetti@baylibre.com> wrote:

> 'aiu-formatter-i2s' already performs the very same reset in
> 'aiu_fifo_i2s_trigger' for all relevant trigger scenarios. There is no
> need to duplicate the operation in the formatter.
>
> Signed-off-by: Valerio Setti <vsetti@baylibre.com>

Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>

> ---
>  sound/soc/meson/aiu-formatter-i2s.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/sound/soc/meson/aiu-formatter-i2s.c b/sound/soc/meson/aiu-formatter-i2s.c
> index b4604734fe88..cb554c2e7ce4 100644
> --- a/sound/soc/meson/aiu-formatter-i2s.c
> +++ b/sound/soc/meson/aiu-formatter-i2s.c
> @@ -13,7 +13,6 @@
>  #define AIU_I2S_SOURCE_DESC_MODE_8CH	BIT(0)
>  #define AIU_I2S_SOURCE_DESC_MODE_24BIT	BIT(5)
>  #define AIU_I2S_SOURCE_DESC_MODE_32BIT	BIT(9)
> -#define AIU_RST_SOFT_I2S_FAST		BIT(0)
>  
>  #define AIU_I2S_DAC_CFG_MSB_FIRST	BIT(2)
>  
> @@ -55,11 +54,11 @@ static int aiu_formatter_i2s_prepare(struct regmap *map,
>  {
>  	/* Always operate in split (classic interleaved) mode */
>  	unsigned int desc = 0;
> -	unsigned int tmp;
>  
> -	/* Reset required to update the pipeline */
> -	regmap_write(map, AIU_RST_SOFT, AIU_RST_SOFT_I2S_FAST);
> -	regmap_read(map, AIU_I2S_SYNC, &tmp);
> +	/*
> +	 * Pipeline reset is already implemented in aiu_fifo_i2s_trigger() at
> +	 * trigger time.
> +	 */
>  
>  	switch (ts->physical_width) {
>  	case 16: /* Nothing to do */

-- 
Jerome