HDMI-Audio: Fix Spinlock-Recursion and Null-Pointer issues

BZ: 21688 37320

Change to prevent Recursive spinlock in trigger.
In middle of start trigger, if HDMI is Pluged-out, the driver
state is disconnected and unplug function calls snd_pcm_stop to
inform the upper layer about disconnection. This internally calls
snd_pcm_stop and stop trigger. Here the lock is recursively
acquired. Solution is to not call snd_pcm_stop if the
substream is active.

Change to prevent Substream NULL during programming buffer.
During successive quick plug and unplug of HDMI cable,
unplug is processed before Start trigger gets to process.
But the trigger state is saved. On unplug the Stop trigger is
called and because it is disconnected it does nothing. Once
cable is plugged in silence is played and the old saved
start trigger causes to retrieve the substream which is NULL
at this point of time. Solution is to clear Trigger state during
unplug. During Plugin inform the upper layer about the event,
if the substream is still active.

HDMI Audio code ported from R2 branch contains Dummy_playback
code. This workaround is no longer needed in R3. (ICS platform)
This patch removes dummy_playback implemtation. Some variables
are renamed for better readability.

Change-Id: I36f4b655316846f8dbf7e0f8935f6a6cff707624
Signed-off-by: Shreyas Neerebailoor <shreyasx.neerebailoor@intel.com>
Reviewed-on: http://android.intel.com:8080/52079
Reviewed-by: Babu, Ramesh <ramesh.babu@intel.com>
Reviewed-by: Agarwal, Vaibhav <vaibhav.agarwal@intel.com>
Reviewed-by: Koul, Vinod <vinod.koul@intel.com>
Reviewed-by: Gupta, ArvindX K <arvindx.k.gupta@intel.com>
Reviewed-by: Hibare, PramodX <pramodx.hibare@intel.com>
Tested-by: Hibare, PramodX <pramodx.hibare@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>

3 files changed, 81 insertions, 198 deletions

diff --git a/sound/drivers/intel_mid_hdmi/intel_mid_hdmi_audio.c b/sound/drivers/intel_mid_hdmi/intel_mid_hdmi_audio.c
index 1b3943398ee..46e36e05e2b 100644
--- a/sound/drivers/intel_mid_hdmi/intel_mid_hdmi_audio.c
+++ b/sound/drivers/intel_mid_hdmi/intel_mid_hdmi_audio.c
@@ -381,12 +381,12 @@ int snd_intelhad_prog_buffer(struct snd_intelhad *intelhaddata,
 	struct snd_pcm_substream *substream;
 
 	substream = intelhaddata->stream_info.had_substream;
-
 	if (!substream) {
 		pr_err("substream is NULL\n");
 		dump_stack();
 		return 0;
 	}
+
 	ring_buf_addr = substream->runtime->dma_addr;
 	ring_buf_size = snd_pcm_lib_buffer_bytes(substream);
 	intelhaddata->stream_info.ring_buf_size = ring_buf_size;
@@ -579,7 +579,8 @@ static int snd_intelhad_open(struct snd_pcm_substream *substream)
 		return -ENODEV;
 	}
 	if (had_stream->process_trigger != NO_TRIGGER) {
-		pr_err("%s:Yet to process some trigger\n", __func__);
+		pr_err("%s:Yet to process some trigger = %d\n", __func__,
+				had_stream->process_trigger);
 		return -EAGAIN;
 	}
 	runtime = substream->runtime;
@@ -807,7 +808,7 @@ int snd_intelhad_start_silence(struct snd_intelhad *intelhaddata)
 	intelhaddata->valid_buf_cnt = HAD_MAX_PERIODS;
 	intelhaddata->curr_buf = HAD_BUF_TYPE_C;
 	had_stream = intelhaddata->private_data;
-	had_stream->stream_status = HAD_RUNNING_SILENCE;
+	had_stream->stream_type = HAD_RUNNING_SILENCE;
 	spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
 
 	had_read_modify(AUD_CONFIG, 1, BIT(0));
@@ -825,7 +826,7 @@ int snd_intelhad_stop_silence(struct snd_intelhad *intelhaddata)
 
 	spin_lock_irqsave(&intelhaddata->had_spinlock, flag_irqs);
 	had_stream = intelhaddata->private_data;
-	had_stream->stream_status = HAD_INIT;
+	had_stream->stream_type = HAD_INIT;
 	spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
 
 	had_read_modify(AUD_CONFIG, 0, BIT(0));
@@ -907,16 +908,14 @@ static int snd_intelhad_pcm_trigger(struct snd_pcm_substream *substream,
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 		pr_debug("Trigger Start\n");
-		stream->substream = substream;
-		stream->stream_status = STREAM_RUNNING;
 
 		/* Disable local INTRs till register prgmng is done */
 		if (had_get_hwstate(intelhaddata)) {
 			pr_err("_START: HDMI cable plugged-out\n");
-			snd_pcm_stop(substream, SNDRV_PCM_STATE_DISCONNECTED);
 			retval = -ENODEV;
 			break;
 		}
+		stream->stream_status = STREAM_RUNNING;
 
 		spin_lock_irqsave(&intelhaddata->had_spinlock, flag_irq);
 		had_stream->process_trigger = PRE_START;
@@ -931,22 +930,17 @@ static int snd_intelhad_pcm_trigger(struct snd_pcm_substream *substream,
 		intelhaddata->stream_info.str_id = 0;
 
 		/* Stop reporting BUFFER_DONE/UNDERRUN to above layers*/
-		had_stream->process_trigger = STOP_TRIGGER;
-		/* Send zero filled data */
-		if (had_stream->stream_status == HAD_RUNNING_DUMMY) {
-			had_stream->stream_status = HAD_INIT;
-			had_stream->process_trigger = NO_TRIGGER;
-			spin_unlock_irqrestore(&intelhaddata->had_spinlock,
-					flag_irq);
-			cancel_delayed_work(&intelhaddata->dummy_audio);
-		} else if (intelhaddata->drv_status != HAD_DRV_DISCONNECTED) {
+
+		if (intelhaddata->drv_status != HAD_DRV_DISCONNECTED) {
+			had_stream->process_trigger = STOP_TRIGGER;
 			spin_unlock_irqrestore(&intelhaddata->had_spinlock,
 					flag_irq);
 			if (!had_get_hwstate(intelhaddata))
 				snd_process_stop_trigger(intelhaddata);
-		} else
+		} else {
 			spin_unlock_irqrestore(&intelhaddata->had_spinlock,
 					flag_irq);
+		}
 		stream->stream_status = STREAM_DROPPED;
 		break;
 
@@ -1000,7 +994,6 @@ static int snd_intelhad_pcm_prepare(struct snd_pcm_substream *substream)
 	pr_debug("rate=%d\n", runtime->rate);
 	pr_debug("channels=%d\n", runtime->channels);
 
-	intelhaddata = snd_pcm_substream_chip(substream);
 	if (intelhaddata->stream_info.str_id) {
 		pr_debug("_prepare is called for existing str_id#%d\n",
 					intelhaddata->stream_info.str_id);
@@ -1122,32 +1115,6 @@ out:
 	return retval;
 }
 
-void dummy_audio_play(struct work_struct *work)
-{
-	struct snd_intelhad *intelhaddata = had_data;
-	struct had_pvt_data *had_stream;
-	unsigned long flag_irqs;
-
-	spin_lock_irqsave(&intelhaddata->had_spinlock, flag_irqs);
-	if (intelhaddata->drv_status != HAD_DRV_DISCONNECTED) {
-		spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
-		pr_debug("HDMI device still connected\n");
-		return;
-	}
-	had_stream = intelhaddata->private_data;
-
-	/* In case _STOP, silence data, return */
-	if (had_stream->stream_status < HAD_RUNNING_STREAM) {
-		spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
-		pr_debug("HDMI device_flag is reset\n");
-		return;
-	}
-
-	spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
-	had_event_handler(HAD_EVENT_AUDIO_BUFFER_DONE, intelhaddata);
-	schedule_delayed_work(&intelhaddata->dummy_audio, intelhaddata->timer);
-}
-
 /*PCM operations structure and the calls back for the same */
 struct snd_pcm_ops snd_intelhad_playback_ops = {
 	.open =		snd_intelhad_open,
@@ -1369,9 +1336,6 @@ static int __devinit hdmi_audio_probe(struct platform_device *devptr)
 	if (retval < 0)
 		goto err;
 
-	/* Initialize dummy audio workqueue */
-	INIT_DELAYED_WORK(&intelhaddata->dummy_audio, dummy_audio_play);
-
 	/* Allocate memory for flat data */
 	intelhaddata->flat_data = kzalloc((MAX_SZ_ZERO_BUF), GFP_KERNEL);
 	if (!intelhaddata->flat_data) {
diff --git a/sound/drivers/intel_mid_hdmi/intel_mid_hdmi_audio.h b/sound/drivers/intel_mid_hdmi/intel_mid_hdmi_audio.h
index ca4de7ca3ed..ab8c673e6ea 100644
--- a/sound/drivers/intel_mid_hdmi/intel_mid_hdmi_audio.h
+++ b/sound/drivers/intel_mid_hdmi/intel_mid_hdmi_audio.h
@@ -98,7 +98,6 @@ enum had_status_stream {
 	HAD_INIT = 0,
 	HAD_RUNNING_SILENCE = 1,
 	HAD_RUNNING_STREAM = 2,
-	HAD_RUNNING_DUMMY = 3,
 };
 
 /**
@@ -425,12 +424,11 @@ struct ring_buf_info {
 struct had_stream_pvt {
 	enum had_stream_status		stream_status;
 	int				stream_ops;
-	struct snd_pcm_substream	*substream;
 	ssize_t				dbg_cum_bytes;
 };
 
 struct had_pvt_data {
-	enum had_status_stream		stream_status;
+	enum had_status_stream		stream_type;
 	enum had_process_trigger	process_trigger;
 };
 
@@ -470,8 +468,6 @@ struct snd_intelhad {
 	unsigned int	aes_bits;
 	int flag_underrun;
 	struct had_pvt_data *private_data;
-	/* Related to sending dummy data */
-	struct delayed_work dummy_audio;
 	unsigned long timer;
 	/*  Related to sending silence data */
 	char *flat_data;
diff --git a/sound/drivers/intel_mid_hdmi/intel_mid_hdmi_audio_if.c b/sound/drivers/intel_mid_hdmi/intel_mid_hdmi_audio_if.c
index f43831d1b89..173f8f29edd 100644
--- a/sound/drivers/intel_mid_hdmi/intel_mid_hdmi_audio_if.c
+++ b/sound/drivers/intel_mid_hdmi/intel_mid_hdmi_audio_if.c
@@ -59,7 +59,7 @@ int hdmi_audio_query(void *haddata, hdmi_audio_event_t event)
 	case HAD_EVENT_QUERY_IS_AUDIO_BUSY:
 		spin_lock_irqsave(&intelhaddata->had_spinlock, flag_irqs);
 
-		if ((had_stream->stream_status > HAD_RUNNING_SILENCE) ||
+		if ((had_stream->stream_type > HAD_RUNNING_SILENCE) ||
 			substream) {
 			spin_unlock_irqrestore(&intelhaddata->had_spinlock,
 						flag_irqs);
@@ -113,7 +113,7 @@ int hdmi_audio_suspend(void *haddata, hdmi_audio_event_t event)
 	substream = intelhaddata->stream_info.had_substream;
 
 	spin_lock_irqsave(&intelhaddata->had_spinlock, flag_irqs);
-	if ((had_stream->stream_status > HAD_RUNNING_SILENCE) || substream) {
+	if ((had_stream->stream_type > HAD_RUNNING_SILENCE) || substream) {
 		spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
 		pr_err("audio stream is active\n");
 		return -EAGAIN;
@@ -229,45 +229,6 @@ static inline int had_chk_intrmiss(struct snd_intelhad *intelhaddata,
 	return intr_count;
 }
 
-static inline int had_start_dummy_playback(struct snd_intelhad *intelhaddata)
-{
-	int retval = 0;
-	enum intel_had_aud_buf_type buf_id;
-	u32 buf_size;
-	struct snd_pcm_substream *substream;
-	struct had_pvt_data *had_stream;
-	u32 msecs, rate, channels;
-	unsigned long flag_irqs;
-
-	pr_debug("Enter:%s", __func__);
-
-	spin_lock_irqsave(&intelhaddata->had_spinlock, flag_irqs);
-	had_stream = intelhaddata->private_data;
-	buf_id = intelhaddata->curr_buf;
-	substream = intelhaddata->stream_info.had_substream;
-
-	if ((had_stream->stream_status < HAD_RUNNING_DUMMY) && substream
-			&& substream->runtime) {
-		had_stream->stream_status = HAD_RUNNING_DUMMY;
-		spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
-		pr_debug("Steam active, start dummy_playback\n");
-		/* In case substream is active, start reporting
-		 * dummy buffer_done interrupts to above ALSA layer.
-		 */
-		buf_size =  intelhaddata->buf_info[buf_id].buf_size;
-		rate = substream->runtime->rate;
-		channels = substream->runtime->channels;
-		msecs = (buf_size*1000)/(rate*channels*4);
-		intelhaddata->timer = msecs_to_jiffies(msecs);
-		schedule_delayed_work(
-				&intelhaddata->dummy_audio,
-				intelhaddata->timer);
-	} else
-		spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
-
-	return retval;
-}
-
 static inline int had_process_pre_start(struct snd_intelhad *intelhaddata,
 		enum intel_had_aud_buf_type buf_id)
 {
@@ -277,10 +238,19 @@ static inline int had_process_pre_start(struct snd_intelhad *intelhaddata,
 	enum intel_had_aud_buf_type inv_start;
 	unsigned long flag_irqs;
 
+
+	spin_lock_irqsave(&intelhaddata->had_spinlock, flag_irqs);
 	had_stream = intelhaddata->private_data;
+	/* Check for device state*/
+	if (intelhaddata->drv_status == HAD_DRV_DISCONNECTED) {
+		spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
+		pr_err("%s:Cable plugged-out\n", __func__);
+		return retval;
+	}
+	spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
 
 	if (intelhaddata->valid_buf_cnt-1 == buf_id) {
-		if (had_stream->stream_status >= HAD_RUNNING_STREAM)
+		if (had_stream->stream_type == HAD_RUNNING_STREAM)
 			buf_id = HAD_BUF_TYPE_A;
 		else	/* Use only silence buffers C & D */
 			buf_id = HAD_BUF_TYPE_C;
@@ -309,7 +279,7 @@ static inline int had_process_pre_start(struct snd_intelhad *intelhaddata,
 	if (buf_id != HAD_BUF_TYPE_A)
 		had_stream->process_trigger = START_TRIGGER;
 	else {
-		had_stream->stream_status = HAD_RUNNING_STREAM;
+		had_stream->stream_type = HAD_RUNNING_STREAM;
 		had_stream->process_trigger = NO_TRIGGER;
 	}
 	spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
@@ -328,22 +298,15 @@ static inline int had_process_start_trigger(struct snd_intelhad *intelhaddata)
 
 	had_stream = intelhaddata->private_data;
 	spin_lock_irqsave(&intelhaddata->had_spinlock, flag_irqs);
-	/* Check for device state
-	 * In case, _DISCONNECTED, start dummy_playback
-	 * if not done
-	 */
+	/* Check for device state*/
 	if (intelhaddata->drv_status == HAD_DRV_DISCONNECTED) {
-		spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
-		pr_debug("Cable plugged-out\n");
-		retval = had_start_dummy_playback(intelhaddata);
-		spin_lock_irqsave(&intelhaddata->had_spinlock, flag_irqs);
 		had_stream->process_trigger = NO_TRIGGER;
-		intelhaddata->curr_buf = HAD_BUF_TYPE_A;
 		spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
+		pr_err("%s:Cable plugged-out\n", __func__);
 		return retval;
 	}
 
-	had_stream->stream_status = HAD_RUNNING_STREAM;
+	had_stream->stream_type = HAD_RUNNING_STREAM;
 	had_stream->process_trigger = NO_TRIGGER;
 	intelhaddata->curr_buf = HAD_BUF_TYPE_A;
 	prg_start = intelhaddata->buff_done;
@@ -364,15 +327,9 @@ static inline int had_process_stop_trigger(struct snd_intelhad *intelhaddata)
 	had_stream = intelhaddata->private_data;
 
 	buf_id = intelhaddata->curr_buf;
-	/* If device disconnected, ignore this interrupt */
-	if (had_stream->stream_status == HAD_RUNNING_DUMMY) {
-		had_stream->stream_status = HAD_INIT;
-		had_stream->process_trigger = NO_TRIGGER;
-		return retval;
-	}
 
 	/* All successive intr for Silence stream */
-	had_stream->stream_status = HAD_RUNNING_SILENCE;
+	had_stream->stream_type = HAD_RUNNING_SILENCE;
 	had_stream->process_trigger = NO_TRIGGER;
 
 	/* If buf_id < HAD_BUF_TYPE_C, ignore */
@@ -417,7 +374,7 @@ int had_process_buffer_done(struct snd_intelhad *intelhaddata)
 	u32 buf_size;
 	struct had_pvt_data *had_stream;
 	int intr_count;
-	enum had_stream_status		stream_status;
+	enum had_status_stream		stream_type;
 	enum had_process_trigger	process_trigger;
 	unsigned long flag_irqs;
 
@@ -426,11 +383,16 @@ int had_process_buffer_done(struct snd_intelhad *intelhaddata)
 	intr_count = 1;
 
 	spin_lock_irqsave(&intelhaddata->had_spinlock, flag_irqs);
+	if (intelhaddata->drv_status == HAD_DRV_DISCONNECTED) {
+		spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
+		pr_err("%s:Device already disconnected\n", __func__);
+		return retval;
+	}
 	buf_id = intelhaddata->curr_buf;
 	intelhaddata->buff_done = buf_id;
 	buff_done = intelhaddata->buff_done;
 	buf_size = intelhaddata->buf_info[buf_id].buf_size;
-	stream_status = had_stream->stream_status;
+	stream_type = had_stream->stream_type;
 	process_trigger = had_stream->process_trigger;
 
 	pr_debug("Enter:%s buf_id=%d", __func__, buf_id);
@@ -441,7 +403,7 @@ int had_process_buffer_done(struct snd_intelhad *intelhaddata)
 	 */
 
 	/* Check for any intr_miss in case of active playback */
-	if ((had_stream->stream_status == HAD_RUNNING_STREAM) &&
+	if ((had_stream->stream_type == HAD_RUNNING_STREAM) &&
 			(had_stream->process_trigger == NO_TRIGGER) &&
 			!flag_en_allbufs) {
 		spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
@@ -484,18 +446,13 @@ int had_process_buffer_done(struct snd_intelhad *intelhaddata)
 
 	intelhaddata->buf_info[buf_id].is_valid = true;
 	if (intelhaddata->valid_buf_cnt-1 == buf_id) {
-		if (had_stream->stream_status >= HAD_RUNNING_STREAM)
+		if (had_stream->stream_type >= HAD_RUNNING_STREAM)
 			intelhaddata->curr_buf = HAD_BUF_TYPE_A;
 		else	/* Use only silence buffers C & D */
 			intelhaddata->curr_buf = HAD_BUF_TYPE_C;
 	} else
 		intelhaddata->curr_buf = buf_id + 1;
 
-	if (had_stream->stream_status == HAD_RUNNING_DUMMY) {
-		spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
-		goto exit;
-	}
-
 	spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
 
 	if (had_get_hwstate(intelhaddata)) {
@@ -519,12 +476,12 @@ int had_process_buffer_done(struct snd_intelhad *intelhaddata)
 	had_read_register(AUD_BUF_A_LENGTH + (buf_id * HAD_REG_WIDTH),
 					&len);
 	pr_debug("%s:Enabled buf[%d]\n", __func__, buf_id);
-exit:
-	/* In case of actual/dummy data,
+
+	/* In case of actual data,
 	 * report buffer_done to above ALSA layer
 	 */
 	buf_size =  intelhaddata->buf_info[buf_id].buf_size;
-	if (stream_status >= HAD_RUNNING_STREAM) {
+	if (stream_type >= HAD_RUNNING_STREAM) {
 		intelhaddata->stream_info.buffer_rendered +=
 			(intr_count * buf_size);
 		stream->period_elapsed(stream->had_substream);
@@ -539,33 +496,30 @@ int had_process_buffer_underrun(struct snd_intelhad *intelhaddata)
 	enum intel_had_aud_buf_type buf_id;
 	struct pcm_stream_info *stream;
 	struct had_pvt_data *had_stream;
-	enum had_stream_status		stream_status;
+	enum had_status_stream stream_type;
 	enum had_process_trigger	process_trigger;
 	u32 hdmi_status;
 	unsigned long flag_irqs;
+	int drv_status;
 
 	had_stream = intelhaddata->private_data;
 	stream = &intelhaddata->stream_info;
 
 	spin_lock_irqsave(&intelhaddata->had_spinlock, flag_irqs);
 	buf_id = intelhaddata->curr_buf;
-	stream_status = had_stream->stream_status;
+	stream_type = had_stream->stream_type;
 	process_trigger = had_stream->process_trigger;
 	intelhaddata->buff_done = buf_id;
-	if (stream_status == HAD_RUNNING_STREAM)
+	drv_status = intelhaddata->drv_status;
+	if (stream_type == HAD_RUNNING_STREAM)
 		intelhaddata->curr_buf = HAD_BUF_TYPE_A;
 	else	/* Use only silence buffers C & D */
 		intelhaddata->curr_buf = HAD_BUF_TYPE_C;
 
 	spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
 
-	pr_debug("Enter:%s buf_id=%d, stream_status=%d, process_trigger=%d\n",
-			__func__, buf_id, stream_status, process_trigger);
-
-	if (stream_status == HAD_RUNNING_DUMMY) {
-		pr_err("_UNDERRUN occured during dummy playback\n");
-		return retval;
-	}
+	pr_debug("Enter:%s buf_id=%d, stream_type=%d, process_trigger=%d\n",
+			__func__, buf_id, stream_type, process_trigger);
 
 	/* Handle Underrun interrupt within Audio Unit */
 	had_write_register(AUD_CONFIG, 0);
@@ -590,8 +544,12 @@ int had_process_buffer_underrun(struct snd_intelhad *intelhaddata)
 	} while (i < MAX_CNT);
 	if (i >= MAX_CNT)
 		pr_err("Unable to clear UNDERRUN bits\n");
+	if (drv_status == HAD_DRV_DISCONNECTED) {
+		pr_err("%s:Device already disconnected\n", __func__);
+		return retval;
+	}
 
-	if (stream_status == HAD_RUNNING_STREAM) {
+	if (stream_type == HAD_RUNNING_STREAM) {
 		if (process_trigger == NO_TRIGGER) {
 			/* Report UNDERRUN error to above layers */
 			intelhaddata->flag_underrun = 1;
@@ -613,11 +571,11 @@ int had_process_buffer_underrun(struct snd_intelhad *intelhaddata)
 			return retval;
 		} else {
 			pr_err("%s:Should never come here\n", __func__);
-			pr_err("stream_status=%d,process_trigger=%d\n",
-					stream_status, process_trigger);
+			pr_err("stream_type=%d,process_trigger=%d\n",
+					stream_type, process_trigger);
 			return retval;
 		}
-	} else if (stream_status == HAD_RUNNING_SILENCE) {
+	} else if (stream_type == HAD_RUNNING_SILENCE) {
 		if (process_trigger < START_TRIGGER)
 			retval = snd_intelhad_start_silence(intelhaddata);
 		else if (process_trigger == START_TRIGGER) {
@@ -625,7 +583,7 @@ int had_process_buffer_underrun(struct snd_intelhad *intelhaddata)
 					flag_irqs);
 			intelhaddata->curr_buf = HAD_BUF_TYPE_A;
 			had_stream->process_trigger = NO_TRIGGER;
-			had_stream->stream_status = HAD_RUNNING_STREAM;
+			had_stream->stream_type = HAD_RUNNING_STREAM;
 			spin_unlock_irqrestore(&intelhaddata->had_spinlock,
 					flag_irqs);
 			had_read_modify(AUD_CONFIG, 1, BIT(0));
@@ -634,8 +592,8 @@ int had_process_buffer_underrun(struct snd_intelhad *intelhaddata)
 			/* Pre start already processed */
 		} else {
 			pr_err("%s:Should never come here\n", __func__);
-			pr_err("stream_status=%d,process_trigger=%d\n",
-					stream_status, process_trigger);
+			pr_err("stream_type=%d,process_trigger=%d\n",
+					stream_type, process_trigger);
 			return retval;
 		}
 	}
@@ -649,7 +607,6 @@ int had_process_hot_plug(struct snd_intelhad *intelhaddata)
 	enum intel_had_aud_buf_type buf_id;
 	struct snd_pcm_substream *substream;
 	struct had_pvt_data *had_stream;
-	enum had_stream_status		stream_status;
 	unsigned long flag_irqs;
 
 	pr_debug("Enter:%s", __func__);
@@ -666,64 +623,27 @@ int had_process_hot_plug(struct snd_intelhad *intelhaddata)
 	buf_id = intelhaddata->curr_buf;
 	intelhaddata->buff_done = buf_id;
 	intelhaddata->drv_status = HAD_DRV_CONNECTED;
-	buf_id = intelhaddata->curr_buf;
-	stream_status = had_stream->stream_status;
 	spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
 
 	pr_debug("Processing HOT_PLUG, buf_id = %d\n", buf_id);
-	if (stream_status == HAD_INIT) {
-		/* Start sending silence data */
-		pr_debug("Start sending SILENCE\n");
-		caps = HDMI_AUDIO_UNDERRUN | HDMI_AUDIO_BUFFER_DONE;
-		retval = had_set_caps(HAD_SET_ENABLE_AUDIO_INT, &caps);
-		retval = had_set_caps(HAD_SET_ENABLE_AUDIO, NULL);
-		retval = snd_intelhad_configure_silence(intelhaddata);
-		retval = snd_intelhad_start_silence(intelhaddata);
-		return retval;
-	}
 
 	/* Safety check */
-	if (!substream) {
-		pr_err("PANIC!!! Should never come here\n");
-		return retval;
+	if (substream) {
+		pr_debug("There should not be active PB from ALSA\n");
+		pr_debug("Signifies, cable is plugged-in even before\n");
+		pr_debug("processing snd_pcm_disconnect\n");
+		/* Set runtime->state to hw_params done */
+		snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
 	}
 
-	if (stream_status == HAD_RUNNING_DUMMY) {
-		spin_lock_irqsave(&intelhaddata->had_spinlock, flag_irqs);
-		had_stream->stream_status = HAD_RUNNING_STREAM;
-		flag_en_allbufs = 1;
-		spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
-		cancel_delayed_work(&intelhaddata->dummy_audio);
-	}
+	/* Start sending silence data */
+	pr_debug("Start sending SILENCE\n");
 	caps = HDMI_AUDIO_UNDERRUN | HDMI_AUDIO_BUFFER_DONE;
 	retval = had_set_caps(HAD_SET_ENABLE_AUDIO_INT, &caps);
 	retval = had_set_caps(HAD_SET_ENABLE_AUDIO, NULL);
 
-	/* Reset HW within Audio unit */
-	had_write_register(AUD_CONFIG, 0);
-	had_write_register(AUD_HDMI_STATUS, 1);
-	had_write_register(AUD_HDMI_STATUS, 0);
-
-	/*Reprogram the registers with addr and length*/
-	pr_debug("Enabling Bottom half buffers after _PLUG\n");
-	/* If all buffs already enabled,
-	 * No need to enable Top half buffers
-	 */
-	if (buf_id == HAD_BUF_TYPE_A)
-		flag_en_allbufs = 0;
-	retval = snd_intelhad_prog_buffer(intelhaddata, buf_id, HAD_BUF_TYPE_D);
-
-	if (substream) { /* continue transfer */
-		snd_intelhad_init_audio_ctrl(substream,
-				intelhaddata, 0);
-		hdmi_audio_mode_change(substream);
-	}
-	if (buf_id == HAD_BUF_TYPE_D) { /* Enable all remaining buffs now*/
-		retval = snd_intelhad_prog_buffer(intelhaddata, HAD_BUF_TYPE_A,
-				(buf_id-1));
-		flag_en_allbufs = 0;
-	}
-
+	snd_intelhad_configure_silence(intelhaddata);
+	retval = snd_intelhad_start_silence(intelhaddata);
 	return retval;
 }
 
@@ -731,7 +651,6 @@ int had_process_hot_unplug(struct snd_intelhad *intelhaddata)
 {
 	int caps, retval = 0;
 	enum intel_had_aud_buf_type buf_id;
-	struct snd_pcm_substream *substream;
 	struct had_pvt_data *had_stream;
 	unsigned long flag_irqs;
 
@@ -739,7 +658,6 @@ int had_process_hot_unplug(struct snd_intelhad *intelhaddata)
 
 	had_stream = intelhaddata->private_data;
 	buf_id = intelhaddata->curr_buf;
-	substream = intelhaddata->stream_info.had_substream;
 
 	spin_lock_irqsave(&intelhaddata->had_spinlock, flag_irqs);
 	if (intelhaddata->drv_status == HAD_DRV_DISCONNECTED) {
@@ -755,15 +673,20 @@ int had_process_hot_unplug(struct snd_intelhad *intelhaddata)
 	}
 
 	intelhaddata->drv_status = HAD_DRV_DISCONNECTED;
-
-	if (had_stream->stream_status == HAD_RUNNING_STREAM) {
-		spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
-		had_start_dummy_playback(intelhaddata);
-	} else {
-		had_stream->stream_status = HAD_INIT;
+	/* Report to above ALSA layer */
+	if (intelhaddata->stream_info.had_substream != NULL) {
+		had_stream->process_trigger = NO_TRIGGER;
 		spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
+		pr_debug("%s: unlock -> sending pcm_stop -> lock\n", __func__);
+		snd_pcm_stop(intelhaddata->stream_info.had_substream,
+				SNDRV_PCM_STATE_DISCONNECTED);
+		spin_lock_irqsave(&intelhaddata->had_spinlock, flag_irqs);
 	}
 
+	had_stream->stream_type = HAD_INIT;
+	spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
+	pr_debug("%s: unlocked -> returned\n", __func__);
+
 	return retval;
 }
 
@@ -822,7 +745,7 @@ int had_event_handler(enum had_event_type event_type, void *data)
 			break;
 		}
 		spin_unlock_irqrestore(&intelhaddata->had_spinlock, flag_irqs);
-		if ((had_stream->stream_status == HAD_RUNNING_STREAM)
+		if ((had_stream->stream_type == HAD_RUNNING_STREAM)
 				&& substream)
 			retval = hdmi_audio_mode_change(substream);
 	break;