[PATCH v14 10/10] drm/mediatek: Use cached audio config when changing resolution

[Bo-Chen Chen <rex-bc.chen@xxxxxxxxxxxx>]

When the audio is playing, we need to use the original configuration to
set the audio instead of using new configuration. Therefore, use the
cached audio configuration during a resolution switch to avoid loss of
sound.

Signed-off-by: Jitao Shi <jitao.shi@xxxxxxxxxxxx>
Signed-off-by: Bo-Chen Chen <rex-bc.chen@xxxxxxxxxxxx>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
---
 drivers/gpu/drm/mediatek/mtk_dp.c | 54 ++++++++++---------------------
 1 file changed, 17 insertions(+), 37 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c
index fa7bb102a105..32fb7be374ed 100644
--- a/drivers/gpu/drm/mediatek/mtk_dp.c
+++ b/drivers/gpu/drm/mediatek/mtk_dp.c
@@ -104,7 +104,7 @@ struct mtk_dp_audio_cfg {
 struct mtk_dp_info {
 	u32 depth;
 	enum dp_pixelformat format;
-	struct mtk_dp_audio_cfg audio_caps;
+	struct mtk_dp_audio_cfg audio_cur_cfg;
 	struct mtk_dp_timings timings;
 };
 
@@ -1858,9 +1858,7 @@ static bool mtk_dp_edid_parse_audio_capabilities(struct mtk_dp *mtk_dp,
 						 struct mtk_dp_audio_cfg *cfg)
 {
 	struct cea_sad *sads;
-	int sad_count;
-	int i;
-	bool ret = false;
+	int ret;
 
 	if (mtk_dp_is_edp(mtk_dp))
 		return false;
@@ -1871,36 +1869,16 @@ static bool mtk_dp_edid_parse_audio_capabilities(struct mtk_dp *mtk_dp,
 		dev_err(mtk_dp->dev, "EDID not found!\n");
 		return false;
 	}
-	sad_count = drm_edid_to_sad(mtk_dp->edid, &sads);
-	mutex_unlock(&mtk_dp->edid_lock);
 
-	if (sad_count <= 0) {
+	ret = drm_edid_to_sad(mtk_dp->edid, &sads);
+	mutex_unlock(&mtk_dp->edid_lock);
+	if (ret <= 0) {
 		drm_info(mtk_dp->drm_dev, "The SADs is NULL\n");
 		return false;
 	}
-
-	for (i = 0; i < sad_count; i++) {
-		int sample_rate, word_length;
-
-		/* Only PCM supported at the moment */
-		if (sads[i].format != HDMI_AUDIO_CODING_TYPE_PCM)
-			continue;
-
-		sample_rate = drm_cea_sad_get_sample_rate(&sads[i]);
-		word_length =
-			drm_cea_sad_get_uncompressed_word_length(&sads[i]);
-		if (sample_rate <= 0 || word_length <= 0)
-			continue;
-
-		cfg->channels = sads[i].channels;
-		cfg->word_length_bits = word_length;
-		cfg->sample_rate = sample_rate;
-		ret = true;
-		break;
-	}
 	kfree(sads);
 
-	return ret;
+	return true;
 }
 
 static void mtk_dp_train_change_mode(struct mtk_dp *mtk_dp)
@@ -2081,13 +2059,13 @@ static int mtk_dp_training(struct mtk_dp *mtk_dp)
 
 	mtk_dp->audio_enable =
 		mtk_dp_edid_parse_audio_capabilities(mtk_dp,
-						     &mtk_dp->info.audio_caps);
+						     &mtk_dp->info.audio_cur_cfg);
 	if (mtk_dp->audio_enable) {
-		mtk_dp_audio_setup(mtk_dp, &mtk_dp->info.audio_caps);
+		mtk_dp_audio_setup(mtk_dp, &mtk_dp->info.audio_cur_cfg);
 		mtk_dp_audio_mute(mtk_dp, false);
 	} else {
-		memset(&mtk_dp->info.audio_caps, 0,
-		       sizeof(mtk_dp->info.audio_caps));
+		memset(&mtk_dp->info.audio_cur_cfg, 0,
+		       sizeof(mtk_dp->info.audio_cur_cfg));
 	}
 
 	return 0;
@@ -2491,6 +2469,9 @@ static void mtk_dp_bridge_atomic_disable(struct drm_bridge *bridge,
 	if (mtk_dp_plug_state(mtk_dp)) {
 		drm_dp_dpcd_writeb(&mtk_dp->aux, DP_SET_POWER, DP_SET_POWER_D3);
 		usleep_range(2000, 3000);
+	} else {
+		memset(&mtk_dp->info.audio_cur_cfg, 0,
+		       sizeof(mtk_dp->info.audio_cur_cfg));
 	}
 
 	mtk_dp_video_mute(mtk_dp, true);
@@ -2701,18 +2682,17 @@ static int mtk_dp_audio_hw_params(struct device *dev, void *data,
 				  struct hdmi_codec_params *params)
 {
 	struct mtk_dp *mtk_dp = dev_get_drvdata(dev);
-	struct mtk_dp_audio_cfg cfg;
 
 	if (!mtk_dp->enabled) {
 		pr_err("%s, DP is not ready!\n", __func__);
 		return -ENODEV;
 	}
 
-	cfg.channels = params->cea.channels;
-	cfg.sample_rate = params->sample_rate;
-	cfg.word_length_bits = 24;
+	mtk_dp->info.audio_cur_cfg.channels = params->cea.channels;
+	mtk_dp->info.audio_cur_cfg.sample_rate = params->sample_rate;
+	mtk_dp->info.audio_cur_cfg.word_length_bits = 24;
 
-	mtk_dp_audio_setup(mtk_dp, &cfg);
+	mtk_dp_audio_setup(mtk_dp, &mtk_dp->info.audio_cur_cfg);
 
 	return 0;
 }
-- 
2.18.0