ASoC: dapm: Modify widget stream name according to prefix

commit fdb6eb0a upstream.

When there is prefix specified, currently we will add this prefix in
widget->name, but not in widget->sname.
it causes failure at snd_soc_dapm_link_dai_widgets:

if (!w->sname || !strstr(w->sname, dai_w->name))

because dai_w->name has prefix added, but w->sname does not.
We should also add prefix for stream name
Signed-off-by: Koro Chen <koro.chen@mediatek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
[bwh: Backported to 3.2:
 - Adjust context
 - s/prefix/dapm->codec->name_prefix]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

sound/soc/soc-dapm.c

@@ -2675,12 +2675,18 @@ int snd_soc_dapm_new_control(struct snd_soc_dapm_context *dapm,
 		kfree(w);
 		return -ENOMEM;
 	}
-	if (dapm->codec && dapm->codec->name_prefix)
+	if (dapm->codec && dapm->codec->name_prefix) {
 		snprintf(w->name, name_len, "%s %s",
 			dapm->codec->name_prefix, widget->name);
-	else
+		if (widget->sname)
+			w->sname = kasprintf(GFP_KERNEL, "%s %s",
+					     dapm->codec->name_prefix,
+					     widget->sname);
+	} else {
 		snprintf(w->name, name_len, "%s", widget->name);
-
+		if (widget->sname)
+			w->sname = kasprintf(GFP_KERNEL, "%s", widget->sname);
+	}
 	switch (w->id) {
 	case snd_soc_dapm_switch:
 	case snd_soc_dapm_mixer: