ASoC: soc-pcm: indicate error message at dpcm_fe/be_dai_startup()

Indicating error message when failed case is very useful for debuging.
In many case, its style is like below.

	int function(...)
	{
		...
		return ret;
	}

	int caller(...)
	{
		...
		ret = function(...);
		if (ret < 0)
			dev_err(...)
		...
	}

This is not so bad, but in this style *each caller* needs to indicate
duplicate same error message, and some caller is forgetting to do it.
And caller can't indicate detail function() error information.

If function() indicates error message, we can get same and
detail information without forgot.

	int function(...)
	{
		...
		if (ret < 0)
			dev_err(...)

		return ret;
	}

	int caller(...)
	{
		...
		ret = function(...);
		...
	}

This patch follow above style at dpcm_fe/be_dai_startup().
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87h7ldutay.wl-kuninori.morimoto.gx@renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-pcm.c

@@ -1475,15 +1475,16 @@ void dpcm_be_dai_stop(struct snd_soc_pcm_runtime *fe, int stream,
 
 int dpcm_be_dai_startup(struct snd_soc_pcm_runtime *fe, int stream)
 {
+	struct snd_soc_pcm_runtime *be;
 	struct snd_soc_dpcm *dpcm;
 	int err, count = 0;
 
 	/* only startup BE DAIs that are either sinks or sources to this FE DAI */
 	for_each_dpcm_be(fe, stream, dpcm) {
+		struct snd_pcm_substream *be_substream;
 
-		struct snd_soc_pcm_runtime *be = dpcm->be;
-		struct snd_pcm_substream *be_substream =
-			snd_soc_dpcm_get_substream(be, stream);
+		be = dpcm->be;
+		be_substream = snd_soc_dpcm_get_substream(be, stream);
 
 		if (!be_substream) {
 			dev_err(be->dev, "ASoC: no backend %s stream\n",
@@ -1535,6 +1536,9 @@ int dpcm_be_dai_startup(struct snd_soc_pcm_runtime *fe, int stream)
 unwind:
 	dpcm_be_dai_startup_rollback(fe, stream, dpcm);
 
+	dev_err(fe->dev, "ASoC: %s() failed at %s (%d)\n",
+		__func__, be->dai_link->name, err);
+
 	return err;
 }
 
@@ -1749,10 +1753,8 @@ static int dpcm_fe_dai_startup(struct snd_pcm_substream *fe_substream)
 	dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_FE);
 
 	ret = dpcm_be_dai_startup(fe, stream);
-	if (ret < 0) {
-		dev_err(fe->dev,"ASoC: failed to start some BEs %d\n", ret);
+	if (ret < 0)
 		goto be_err;
-	}
 
 	dev_dbg(fe->dev, "ASoC: open FE %s\n", fe->dai_link->name);
 
@@ -1776,6 +1778,10 @@ static int dpcm_fe_dai_startup(struct snd_pcm_substream *fe_substream)
 		dpcm_be_dai_startup_unwind(fe, stream);
 be_err:
 	dpcm_set_fe_update_state(fe, stream, SND_SOC_DPCM_UPDATE_NO);
+
+	if (ret < 0)
+		dev_err(fe->dev, "%s() failed (%d)\n", __func__, ret);
+
 	return ret;
 }