HDMI: update `silent_stream' implementation

Some struct fiels were missing and the kernel was using an
old failing implementation of `silent_stream_enable'.

sound/pci/hda/patch_hdmi.c

@@ -78,6 +78,7 @@ struct hdmi_spec_per_pin {
 	int pcm_idx; /* which pcm is attached. -1 means no pcm is attached */
 	int repoll_count;
 	bool setup; /* the stream has been set up by prepare callback */
+	bool silent_stream;
 	int channels; /* current number of channels */
 	bool non_pcm;
 	bool chmap_set;		/* channel-map override by ALSA API? */
@@ -1642,27 +1643,65 @@ static void hdmi_present_sense_via_verbs(struct hdmi_spec_per_pin *per_pin,
 	snd_hda_power_down_pm(codec);
 }
 
+#define I915_SILENT_RATE		48000
+#define I915_SILENT_CHANNELS	2
+#define I915_SILENT_FORMAT		SNDRV_PCM_FORMAT_S16_LE
+#define I915_SILENT_FORMAT_BITS	16
+#define I915_SILENT_FMT_MASK	0xf
+
 static void silent_stream_enable(struct hda_codec *codec,
-				struct hdmi_spec_per_pin *per_pin)
+				 				 struct hdmi_spec_per_pin *per_pin)
 {
-	unsigned int newval, oldval;
-
-	codec_dbg(codec, "hdmi: enabling silent stream for NID %d\n",
-			per_pin->pin_nid);
+	struct hdmi_spec *spec = codec->spec;
+	struct hdmi_spec_per_cvt *per_cvt;
+	int cvt_idx, pin_idx, err;
+	unsigned int format;
 
 	mutex_lock(&per_pin->lock);
 
-	if (!per_pin->channels)
-		per_pin->channels = 2;
+	if (per_pin->setup) {
+		codec_dbg(codec, "hdmi: PCM already open, no silent stream\n");
+		goto unlock_out;
+	}
 
-	oldval = snd_hda_codec_read(codec, per_pin->pin_nid, 0,
-			AC_VERB_GET_CONV, 0);
-	newval = (oldval & 0xF0) | 0xF;
-	snd_hda_codec_write(codec, per_pin->pin_nid, 0,
-			AC_VERB_SET_CHANNEL_STREAMID, newval);
+	pin_idx = pin_id_to_pin_index(codec, per_pin->pin_nid, per_pin->dev_id);
+	err = hdmi_choose_cvt(codec, pin_idx, &cvt_idx);
+	if (err) {
+		codec_err(codec, "hdmi: no free converter to enable silent mode\n");
+		goto unlock_out;
+	}
 
+	per_cvt = get_cvt(spec, cvt_idx);
+	per_cvt->assigned = 1;
+	per_pin->cvt_nid = per_cvt->cvt_nid;
+	per_pin->silent_stream = true;
+
+	codec_dbg(codec, "hdmi: enabling silent stream pin-NID=0x%x cvt-NID=0x%x\n",
+		  per_pin->pin_nid, per_cvt->cvt_nid);
+
+	snd_hda_set_dev_select(codec, per_pin->pin_nid, per_pin->dev_id);
+	snd_hda_codec_write_cache(codec, per_pin->pin_nid, 0,
+				  AC_VERB_SET_CONNECT_SEL,
+				  per_pin->mux_idx);
+
+	/* configure unused pins to choose other converters */
+	pin_cvt_fixup(codec, per_pin, 0);
+
+	snd_hdac_sync_audio_rate(&codec->core, per_pin->pin_nid,
+				 per_pin->dev_id, I915_SILENT_RATE);
+
+	/* trigger silent stream generation in hw */
+	format = snd_hdac_calc_stream_format(I915_SILENT_RATE, I915_SILENT_CHANNELS,
+					     I915_SILENT_FORMAT, I915_SILENT_FORMAT_BITS, 0);
+	snd_hda_codec_setup_stream(codec, per_pin->cvt_nid,
+				   I915_SILENT_FMT_MASK, I915_SILENT_FMT_MASK, format);
+	usleep_range(100, 200);
+	snd_hda_codec_setup_stream(codec, per_pin->cvt_nid, I915_SILENT_FMT_MASK, 0, format);
+
+	per_pin->channels = I915_SILENT_CHANNELS;
 	hdmi_setup_audio_infoframe(codec, per_pin, per_pin->non_pcm);
 
+ unlock_out:
 	mutex_unlock(&per_pin->lock);
 }