ALSA: hda/hdmi: Add module option to disable audio component binding

As the recent regression showed, we want sometimes to turn off the
audio component binding just for debugging.  This patch adds the
module option to control it easily without compilation.

Fixes: ade49db ("ALSA: hda/hdmi - Allow audio component for AMD/ATI and Nvidia HDMI")
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=207223
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200415162523.27499-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/patch_hdmi.c

@@ -38,6 +38,10 @@ static bool static_hdmi_pcm;
 module_param(static_hdmi_pcm, bool, 0644);
 MODULE_PARM_DESC(static_hdmi_pcm, "Don't restrict PCM parameters per ELD info");
 
+static bool enable_acomp = true;
+module_param(enable_acomp, bool, 0444);
+MODULE_PARM_DESC(enable_acomp, "Enable audio component binding (default=yes)");
+
 struct hdmi_spec_per_cvt {
 	hda_nid_t cvt_nid;
 	int assigned;
@@ -2505,6 +2509,11 @@ static void generic_acomp_init(struct hda_codec *codec,
 {
 	struct hdmi_spec *spec = codec->spec;
 
+	if (!enable_acomp) {
+		codec_info(codec, "audio component disabled by module option\n");
+		return;
+	}
+
 	spec->port2pin = port2pin;
 	setup_drm_audio_ops(codec, ops);
 	if (!snd_hdac_acomp_init(&codec->bus->core, &spec->drm_audio_ops,