ASoC: Stop dummy from overriding hwparams

In case that there are other components assigned to runtime device,
depending on order dummy component can override their params with its
own, which shouldn't happen. Check if there are any other components
assigned to rtd and if so, skip setting hwparams.

Occurs when using topology where 'snd-soc-dummy' gets assigned by
default as codec and platform component.

Alternative approach would be to copy whole dummy handling and rename it
to "snd-soc-null" or something similar. And remove hwparams assignment
to make it really do nothing.
Signed-off-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Link: https://lore.kernel.org/r/20211015161257.27052-7-cezary.rojewski@intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-utils.c

@@ -63,10 +63,23 @@ static const struct snd_pcm_hardware dummy_dma_hardware = {
 	.periods_max		= 128,
 };
 
+
+static const struct snd_soc_component_driver dummy_platform;
+
 static int dummy_dma_open(struct snd_soc_component *component,
 			  struct snd_pcm_substream *substream)
 {
 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+	int i;
+
+	/*
+	 * If there are other components associated with rtd, we shouldn't
+	 * override their hwparams
+	 */
+	for_each_rtd_components(rtd, i, component) {
+		if (component->driver == &dummy_platform)
+			return 0;
+	}
 
 	/* BE's dont need dummy params */
 	if (!rtd->dai_link->no_pcm)