linux-kernel - [PATCH] ASoC: codecs: lpass-wsa-macro: Fix speaker quality distortion

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Message-ID: <20250831151401.30897-2-krzysztof.kozlowski@linaro.org>
Date: Sun, 31 Aug 2025 17:14:02 +0200
From: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To: Srinivas Kandagatla <srini@...nel.org>,
	Liam Girdwood <lgirdwood@...il.com>,
	Mark Brown <broonie@...nel.org>,
	Jaroslav Kysela <perex@...ex.cz>,
	Takashi Iwai <tiwai@...e.com>,
	Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>,
	linux-sound@...r.kernel.org,
	linux-arm-msm@...r.kernel.org,
	linux-kernel@...r.kernel.org
Cc: Alexey Klimov <alexey.klimov@...aro.org>
Subject: [PATCH] ASoC: codecs: lpass-wsa-macro: Fix speaker quality distortion

Commit bb4a0f497bc1 ("ASoC: codecs: lpass: Drop unused
AIF_INVALID first DAI identifier") removed first entry in enum with DAI
identifiers, because it looked unused.  Turns out that there is a
relation between DAI ID and "WSA RX0 Mux"-like kcontrols (which use
"rx_mux_text" array).  That "rx_mux_text" array used first three entries
of DAI IDs enum, with value '0' being invalid.

The value passed tp "WSA RX0 Mux"-like kcontrols was used as DAI ID and
set to configure active channel count and mask, which are arrays indexed
by DAI ID.

After removal of first AIF_INVALID DAI identifier, this kcontrol was
updating wrong entries in active channel count and mask arrays which was
visible in reduced quality (distortions) during speaker playback on
several boards like Lenovo T14s laptop and Qualcomm SM8550-based boards.

Reported-by: Alexey Klimov <alexey.klimov@...aro.org>
Fixes: bb4a0f497bc1 ("ASoC: codecs: lpass: Drop unused AIF_INVALID first DAI identifier")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>

---

Reported via IRC.
Fix for current v6.17-RC cycle.

I will be investigating rest of lpass macro codecs a bit later.
---
 sound/soc/codecs/lpass-wsa-macro.c | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/sound/soc/codecs/lpass-wsa-macro.c b/sound/soc/codecs/lpass-wsa-macro.c
index da6adb3de21d..d7eec9fdaf9c 100644
--- a/sound/soc/codecs/lpass-wsa-macro.c
+++ b/sound/soc/codecs/lpass-wsa-macro.c
@@ -368,6 +368,7 @@ static struct interp_sample_rate int_mix_sample_rate_val[] = {
 	{192000, 0x6},	/* 192K */
 };
 
+/* Matches also rx_mux_text */
 enum {
 	WSA_MACRO_AIF1_PB,
 	WSA_MACRO_AIF_MIX1_PB,
@@ -465,6 +466,7 @@ static const char *const rx_mix_ec_text[] = {
 	"ZERO", "RX_MIX_TX0", "RX_MIX_TX1"
 };
 
+/* Order must match WSA_MACRO_MAX_DAIS enum (offset by 1) */
 static const char *const rx_mux_text[] = {
 	"ZERO", "AIF1_PB", "AIF_MIX1_PB"
 };
@@ -2207,6 +2209,7 @@ static int wsa_macro_rx_mux_put(struct snd_kcontrol *kcontrol,
 	u32 rx_port_value = ucontrol->value.integer.value[0];
 	u32 bit_input;
 	u32 aif_rst;
+	unsigned int dai_id;
 	struct wsa_macro *wsa = snd_soc_component_get_drvdata(component);
 
 	aif_rst = wsa->rx_port_value[widget->shift];
@@ -2224,17 +2227,22 @@ static int wsa_macro_rx_mux_put(struct snd_kcontrol *kcontrol,
 
 	switch (rx_port_value) {
 	case 0:
-		if (wsa->active_ch_cnt[aif_rst]) {
-			clear_bit(bit_input,
-				  &wsa->active_ch_mask[aif_rst]);
-			wsa->active_ch_cnt[aif_rst]--;
+		/*
+		 * active_ch_cnt and active_ch_mask use DAI IDs (WSA_MACRO_MAX_DAIS).
+		 * active_ch_cnt == 0 was tested in if() above.
+		 */
+		dai_id = aif_rst - 1;
+		if (wsa->active_ch_cnt[dai_id]) {
+			clear_bit(bit_input, &wsa->active_ch_mask[dai_id]);
+			wsa->active_ch_cnt[dai_id]--;
 		}
 		break;
 	case 1:
 	case 2:
-		set_bit(bit_input,
-			&wsa->active_ch_mask[rx_port_value]);
-		wsa->active_ch_cnt[rx_port_value]++;
+		/* active_ch_cnt and active_ch_mask use DAI IDs (WSA_MACRO_MAX_DAIS). */
+		dai_id = rx_port_value - 1;
+		set_bit(bit_input, &wsa->active_ch_mask[dai_id]);
+		wsa->active_ch_cnt[dai_id]++;
 		break;
 	default:
 		dev_err(component->dev,
-- 
2.48.1