diff --git a/hal/Android.mk b/hal/Android.mk
index e7ba38f..72042d1 100644
--- a/hal/Android.mk
+++ b/hal/Android.mk
@@ -256,6 +256,14 @@
     LOCAL_SRC_FILES += audio_extn/listen.c
 endif
 
+ifeq ($(strip $(AUDIO_FEATURE_ENABLED_EXT_HDMI)),true)
+    LOCAL_CFLAGS += -DAUDIO_EXTERNAL_HDMI_ENABLED
+ifeq ($(strip $(AUDIO_FEATURE_ENABLED_HDMI_PASSTHROUGH)),true)
+    LOCAL_C_INCLUDES += $(TARGET_OUT_HEADERS)/mm-audio/audio-parsers
+    LOCAL_SHARED_LIBRARIES += libaudioparsers
+endif
+endif
+
 ifeq ($(strip $(BOARD_SUPPORTS_SOUND_TRIGGER)),true)
     LOCAL_CFLAGS += -DSOUND_TRIGGER_ENABLED
     LOCAL_CFLAGS += -DSOUND_TRIGGER_PLATFORM_NAME=$(TARGET_BOARD_PLATFORM)
diff --git a/hal/audio_extn/audio_extn.h b/hal/audio_extn/audio_extn.h
index dca965a..3645cdb 100644
--- a/hal/audio_extn/audio_extn.h
+++ b/hal/audio_extn/audio_extn.h
@@ -510,4 +510,10 @@
 void audio_extn_perf_lock_acquire(void);
 void audio_extn_perf_lock_release(void);
 #endif /* KPI_OPTIMIZE_ENABLED */
+
+#ifndef AUDIO_EXTERNAL_HDMI_ENABLED
+#define audio_utils_set_hdmi_channel_status(out, buffer, bytes) (0)
+#else
+void audio_utils_set_hdmi_channel_status(struct stream_out *out, char * buffer, size_t bytes);
+#endif
 #endif /* AUDIO_EXTN_H */
diff --git a/hal/audio_extn/utils.c b/hal/audio_extn/utils.c
index b9e2a40..38dbb46 100644
--- a/hal/audio_extn/utils.c
+++ b/hal/audio_extn/utils.c
@@ -35,6 +35,12 @@
 #include "audio_extn.h"
 #include "voice.h"
 
+#ifdef AUDIO_EXTERNAL_HDMI_ENABLED
+#ifdef HDMI_PASSTHROUGH_ENABLED
+#include "audio_parsers.h"
+#endif
+#endif
+
 #define AUDIO_OUTPUT_POLICY_VENDOR_CONFIG_FILE "/vendor/etc/audio_output_policy.conf"
 
 #define OUTPUTS_TAG "outputs"
@@ -52,6 +58,21 @@
 #define BASE_TABLE_SIZE 64
 #define MAX_BASEINDEX_LEN 256
 
+#ifdef AUDIO_EXTERNAL_HDMI_ENABLED
+#define PROFESSIONAL        (1<<0)      /* 0 = consumer, 1 = professional */
+#define NON_LPCM            (1<<1)      /* 0 = audio, 1 = non-audio */
+#define SR_44100            (0<<0)      /* 44.1kHz */
+#define SR_NOTID            (1<<0)      /* non indicated */
+#define SR_48000            (2<<0)      /* 48kHz */
+#define SR_32000            (3<<0)      /* 32kHz */
+#define SR_22050            (4<<0)      /* 22.05kHz */
+#define SR_24000            (6<<0)      /* 24kHz */
+#define SR_88200            (8<<0)      /* 88.2kHz */
+#define SR_96000            (10<<0)     /* 96kHz */
+#define SR_176400           (12<<0)     /* 176.4kHz */
+#define SR_192000           (14<<0)     /* 192kHz */
+
+#endif
 struct string_to_enum {
     const char *name;
     uint32_t value;
@@ -765,3 +786,136 @@
     outp[k] = '\0';
     return k;
 }
+
+#ifdef AUDIO_EXTERNAL_HDMI_ENABLED
+
+void get_default_compressed_channel_status(
+                                  unsigned char *channel_status)
+{
+     int32_t status = 0;
+     unsigned char bit_index;
+     memset(channel_status,0,24);
+
+     /* block start bit in preamble bit 3 */
+     channel_status[0] |= PROFESSIONAL;
+     //compre out
+     channel_status[0] |= NON_LPCM;
+     // sample rate; fixed 48K for default/transcode
+     channel_status[3] |= SR_48000;
+}
+
+#ifdef HDMI_PASSTHROUGH_ENABLED
+int32_t get_compressed_channel_status(void *audio_stream_data,
+                                                   uint32_t audio_frame_size,
+                                                   unsigned char *channel_status,
+                                                   enum audio_parser_code_type codec_type)
+                                                   // codec_type - AUDIO_PARSER_CODEC_AC3
+                                                   //            - AUDIO_PARSER_CODEC_DTS
+{
+     unsigned char *stream;
+     int ret = 0;
+     stream = (unsigned char *)audio_stream_data;
+
+     if (audio_stream_data == NULL || audio_frame_size == 0) {
+         ALOGW("no buffer to get channel status, return default for compress");
+         get_default_compressed_channel_status(channel_status);
+         return ret;
+     }
+
+     memset(channel_status,0,24);
+     if(init_audio_parser(stream, audio_frame_size, codec_type) == -1)
+     {
+         ALOGE("init audio parser failed");
+         return -1;
+     }
+     ret = get_channel_status(channel_status, codec_type);
+     return ret;
+
+}
+
+#endif
+
+void get_lpcm_channel_status(uint32_t sampleRate,
+                                                  unsigned char *channel_status)
+{
+     int32_t status = 0;
+     unsigned char bit_index;
+     memset(channel_status,0,24);
+     /* block start bit in preamble bit 3 */
+     channel_status[0] |= PROFESSIONAL;
+     //LPCM OUT
+     channel_status[0] &= ~NON_LPCM;
+
+     switch (sampleRate) {
+         case 8000:
+         case 11025:
+         case 12000:
+         case 16000:
+         case 22050:
+             channel_status[3] |= SR_NOTID;
+         case 24000:
+             channel_status[3] |= SR_24000;
+             break;
+         case 32000:
+             channel_status[3] |= SR_32000;
+             break;
+         case 44100:
+             channel_status[3] |= SR_44100;
+             break;
+         case 48000:
+             channel_status[3] |= SR_48000;
+             break;
+         case 88200:
+             channel_status[3] |= SR_88200;
+             break;
+         case 96000:
+             channel_status[3] |= SR_96000;
+             break;
+         case 176400:
+             channel_status[3] |= SR_176400;
+             break;
+         case 192000:
+            channel_status[3] |= SR_192000;
+             break;
+         default:
+             ALOGV("Invalid sample_rate %u\n", sampleRate);
+             status = -1;
+             break;
+     }
+}
+
+void audio_utils_set_hdmi_channel_status(struct stream_out *out, char * buffer, size_t bytes)
+{
+    unsigned char channel_status[24]={0};
+    struct snd_aes_iec958 iec958;
+    const char *mixer_ctl_name = "IEC958 Playback PCM Stream";
+    struct mixer_ctl *ctl;
+    int i=0;
+#ifdef HDMI_PASSTHROUGH_ENABLED
+    if (audio_extn_is_dolby_format(out->format) &&
+        /*TODO:Extend code to support DTS passthrough*/
+        /*set compressed channel status bits*/
+        audio_extn_dolby_is_passthrough_stream(out->flags)){
+        get_compressed_channel_status(buffer, bytes, channel_status, AUDIO_PARSER_CODEC_AC3);
+    } else
+#endif
+    {
+        /*set channel status bit for LPCM*/
+        get_lpcm_channel_status(out->sample_rate, channel_status);
+    }
+
+    memcpy(iec958.status, channel_status,sizeof(iec958.status));
+    ctl = mixer_get_ctl_by_name(out->dev->mixer, mixer_ctl_name);
+    if (!ctl) {
+            ALOGE("%s: Could not get ctl for mixer cmd - %s",
+                  __func__, mixer_ctl_name);
+            return;
+    }
+    if (mixer_ctl_set_array(ctl, &iec958, sizeof(iec958)) < 0) {
+        ALOGE("%s: Could not set channel status for ext HDMI ",
+              __func__);
+        return;
+    }
+
+}
+#endif
diff --git a/hal/audio_hw.c b/hal/audio_hw.c
index d5db25b..b98d71b 100644
--- a/hal/audio_hw.c
+++ b/hal/audio_hw.c
@@ -601,6 +601,9 @@
             audio_route_reset_and_update_path(adev->audio_route, device_name);
         }
 
+        if (snd_device == SND_DEVICE_OUT_HDMI)
+            adev->is_channel_status_set = false;
+
         audio_extn_dev_arbi_release(snd_device);
         audio_extn_sound_trigger_update_device_status(snd_device,
                                         ST_EVENT_SND_DEVICE_FREE);
@@ -1190,6 +1193,20 @@
     return ret;
 }
 
+void lock_input_stream(struct stream_in *in)
+{
+    pthread_mutex_lock(&in->pre_lock);
+    pthread_mutex_lock(&in->lock);
+    pthread_mutex_unlock(&in->pre_lock);
+}
+
+void lock_output_stream(struct stream_out *out)
+{
+    pthread_mutex_lock(&out->pre_lock);
+    pthread_mutex_lock(&out->lock);
+    pthread_mutex_unlock(&out->pre_lock);
+}
+
 /* must be called with out->lock locked */
 static int send_offload_cmd_l(struct stream_out* out, int command)
 {
@@ -1278,7 +1295,7 @@
     prctl(PR_SET_NAME, (unsigned long)"Offload Callback", 0, 0, 0);
 
     ALOGV("%s", __func__);
-    pthread_mutex_lock(&out->lock);
+    lock_output_stream(out);
     for (;;) {
         struct offload_cmd *cmd = NULL;
         stream_callback_event_t event;
@@ -1357,7 +1374,7 @@
             ALOGE("%s unknown command received: %d", __func__, cmd->cmd);
             break;
         }
-        pthread_mutex_lock(&out->lock);
+        lock_output_stream(out);
         out->offload_thread_blocked = false;
         pthread_cond_signal(&out->cond);
         if (send_callback && out->offload_callback) {
@@ -1389,7 +1406,7 @@
 
 static int destroy_offload_callback_thread(struct stream_out *out)
 {
-    pthread_mutex_lock(&out->lock);
+    lock_output_stream(out);
     stop_compressed_output_l(out);
     send_offload_cmd_l(out, OFFLOAD_CMD_EXIT);
 
@@ -1848,7 +1865,7 @@
         return 0;
     }
 
-    pthread_mutex_lock(&out->lock);
+    lock_output_stream(out);
     if (!out->standby) {
         if (adev->adm_deregister_stream)
             adev->adm_deregister_stream(adev->adm_data, out->handle);
@@ -1937,7 +1954,7 @@
     err = str_parms_get_str(parms, AUDIO_PARAMETER_STREAM_ROUTING, value, sizeof(value));
     if (err >= 0) {
         val = atoi(value);
-        pthread_mutex_lock(&out->lock);
+        lock_output_stream(out);
         pthread_mutex_lock(&adev->lock);
 
         /*
@@ -2001,7 +2018,7 @@
         pthread_mutex_unlock(&adev->lock);
     }
     if (is_offload_usecase(out->usecase)) {
-        pthread_mutex_lock(&out->lock);
+        lock_output_stream(out);
         parse_compress_metadata(out, parms);
 
         audio_extn_dts_create_state_notifier_node(out->usecase);
@@ -2157,7 +2174,7 @@
     int snd_scard_state = get_snd_card_state(adev);
     ssize_t ret = 0;
 
-    pthread_mutex_lock(&out->lock);
+    lock_output_stream(out);
 
     if (SND_CARD_STATE_OFFLINE == snd_scard_state) {
         // increase written size during SSR to avoid mismatch
@@ -2194,6 +2211,11 @@
             adev->adm_register_output_stream(adev->adm_data, out->handle, out->flags);
     }
 
+    if (adev->is_channel_status_set == false && (out->devices & AUDIO_DEVICE_OUT_AUX_DIGITAL)){
+        audio_utils_set_hdmi_channel_status(out, buffer, bytes);
+        adev->is_channel_status_set = true;
+    }
+
     if (is_offload_usecase(out->usecase)) {
         ALOGVV("copl(%p): writing buffer (%zu bytes) to compress device", out, bytes);
         if (out->send_new_metadata) {
@@ -2297,7 +2319,7 @@
     *dsp_frames = 0;
     if (is_offload_usecase(out->usecase)) {
         ssize_t ret = 0;
-        pthread_mutex_lock(&out->lock);
+        lock_output_stream(out);
         if (out->compr != NULL) {
             ret = compress_get_tstamp(out->compr, (unsigned long *)dsp_frames,
                     &out->sample_rate);
@@ -2356,7 +2378,7 @@
     int ret = -1;
     unsigned long dsp_frames;
 
-    pthread_mutex_lock(&out->lock);
+    lock_output_stream(out);
 
     if (is_offload_usecase(out->usecase)) {
         if (out->compr != NULL) {
@@ -2408,7 +2430,7 @@
     struct stream_out *out = (struct stream_out *)stream;
 
     ALOGV("%s", __func__);
-    pthread_mutex_lock(&out->lock);
+    lock_output_stream(out);
     out->offload_callback = callback;
     out->offload_cookie = cookie;
     pthread_mutex_unlock(&out->lock);
@@ -2422,7 +2444,7 @@
     ALOGV("%s", __func__);
     if (is_offload_usecase(out->usecase)) {
         ALOGD("copl(%p):pause compress driver", out);
-        pthread_mutex_lock(&out->lock);
+        lock_output_stream(out);
         if (out->compr != NULL && out->offload_state == OFFLOAD_STATE_PLAYING) {
             struct audio_device *adev = out->dev;
             int snd_scard_state = get_snd_card_state(adev);
@@ -2450,7 +2472,7 @@
     if (is_offload_usecase(out->usecase)) {
         ALOGD("copl(%p):resume compress driver", out);
         status = 0;
-        pthread_mutex_lock(&out->lock);
+        lock_output_stream(out);
         if (out->compr != NULL && out->offload_state == OFFLOAD_STATE_PAUSED) {
             struct audio_device *adev = out->dev;
             int snd_scard_state = get_snd_card_state(adev);
@@ -2475,7 +2497,7 @@
     int status = -ENOSYS;
     ALOGV("%s", __func__);
     if (is_offload_usecase(out->usecase)) {
-        pthread_mutex_lock(&out->lock);
+        lock_output_stream(out);
         if (type == AUDIO_DRAIN_EARLY_NOTIFY)
             status = send_offload_cmd_l(out, OFFLOAD_CMD_PARTIAL_DRAIN);
         else
@@ -2491,7 +2513,7 @@
     ALOGV("%s", __func__);
     if (is_offload_usecase(out->usecase)) {
         ALOGD("copl(%p):calling compress flush", out);
-        pthread_mutex_lock(&out->lock);
+        lock_output_stream(out);
         stop_compressed_output_l(out);
         pthread_mutex_unlock(&out->lock);
         ALOGD("copl(%p):out of compress flush", out);
@@ -2563,7 +2585,7 @@
         return status;
     }
 
-    pthread_mutex_lock(&in->lock);
+    lock_input_stream(in);
     if (!in->standby && in->is_st_session) {
         ALOGD("%s: sound trigger pcm stop lab", __func__);
         audio_extn_sound_trigger_stop_lab(in);
@@ -2608,7 +2630,7 @@
 
     if (!parms)
         goto error;
-    pthread_mutex_lock(&in->lock);
+    lock_input_stream(in);
     pthread_mutex_lock(&adev->lock);
 
     err = str_parms_get_str(parms, AUDIO_PARAMETER_STREAM_INPUT_SOURCE, value, sizeof(value));
@@ -2692,7 +2714,7 @@
     int i, ret = -1;
     int snd_scard_state = get_snd_card_state(adev);
 
-    pthread_mutex_lock(&in->lock);
+    lock_input_stream(in);
 
     if (in->is_st_session) {
         ALOGVV(" %s: reading on st session bytes=%zu", __func__, bytes);
@@ -2792,7 +2814,7 @@
     if (status != 0)
         return status;
 
-    pthread_mutex_lock(&in->lock);
+    lock_input_stream(in);
     pthread_mutex_lock(&in->dev->lock);
     if ((in->source == AUDIO_SOURCE_VOICE_COMMUNICATION) &&
             in->enable_aec != enable &&
@@ -2860,6 +2882,7 @@
     }
 
     pthread_mutex_init(&out->lock, (const pthread_mutexattr_t *) NULL);
+    pthread_mutex_init(&out->pre_lock, (const pthread_mutexattr_t *) NULL);
     pthread_cond_init(&out->cond, (const pthread_condattr_t *) NULL);
 
     if (devices == AUDIO_DEVICE_NONE)
@@ -3524,6 +3547,7 @@
         devices, &in->stream, handle, source);
 
     pthread_mutex_init(&in->lock, (const pthread_mutexattr_t *) NULL);
+    pthread_mutex_init(&in->pre_lock, (const pthread_mutexattr_t *) NULL);
 
     in->stream.common.get_sample_rate = in_get_sample_rate;
     in->stream.common.set_sample_rate = in_set_sample_rate;
@@ -3781,6 +3805,7 @@
     list_init(&adev->usecase_list);
     adev->cur_wfd_channels = 2;
     adev->offload_usecases_state = 0;
+    adev->is_channel_status_set = false;
 
     pthread_mutex_init(&adev->snd_card_status.lock, (const pthread_mutexattr_t *) NULL);
     adev->snd_card_status.state = SND_CARD_STATE_OFFLINE;
diff --git a/hal/audio_hw.h b/hal/audio_hw.h
index 5c1ea1d..dc0970f 100644
--- a/hal/audio_hw.h
+++ b/hal/audio_hw.h
@@ -184,6 +184,7 @@
 struct stream_out {
     struct audio_stream_out stream;
     pthread_mutex_t lock; /* see note below on mutex acquisition order */
+    pthread_mutex_t pre_lock; /* acquire before lock to avoid DOS by playback thread */
     pthread_cond_t  cond;
     struct pcm_config config;
     struct compr_config compr_config;
@@ -228,6 +229,7 @@
 struct stream_in {
     struct audio_stream_in stream;
     pthread_mutex_t lock; /* see note below on mutex acquisition order */
+    pthread_mutex_t pre_lock; /* acquire before lock to avoid DOS by playback thread */
     struct pcm_config config;
     struct pcm *pcm;
     int standby;
@@ -327,6 +329,7 @@
     int snd_card;
     unsigned int cur_codec_backend_samplerate;
     unsigned int cur_codec_backend_bit_width;
+    bool is_channel_status_set;
     void *platform;
     unsigned int offload_usecases_state;
     void *visualizer_lib;
diff --git a/hal/msm8916/platform.c b/hal/msm8916/platform.c
index baec1e0..03ae642 100644
--- a/hal/msm8916/platform.c
+++ b/hal/msm8916/platform.c
@@ -4146,15 +4146,12 @@
     }
     edid_data[0] = count;
     memcpy(&edid_data[1], block, count);
-
-#ifdef AUDIO_FEATURE_ENABLED_HDMI_EDID
     if (!edid_get_sink_caps(info, edid_data)) {
         ALOGE("%s: Failed to get HDMI sink capabilities", __func__);
         goto fail;
     }
     my_data->edid_valid = true;
     return 0;
-#endif
 fail:
     if (my_data->edid_info) {
         free(my_data->edid_info);
diff --git a/hal/msm8974/platform.c b/hal/msm8974/platform.c
index 5cb18fd..d693aae 100644
--- a/hal/msm8974/platform.c
+++ b/hal/msm8974/platform.c
@@ -1286,7 +1286,12 @@
             continue;
         }
 
-        snd_card_name = mixer_get_name(adev->mixer);
+        snd_card_name = strdup(mixer_get_name(adev->mixer));
+        if (!snd_card_name) {
+            ALOGE("failed to allocate memory for snd_card_name\n");
+            free(my_data);
+            return NULL;
+        }
         ALOGV("%s: snd_card_name: %s", __func__, snd_card_name);
 
         my_data->hw_info = hw_info_init(snd_card_name);
@@ -1348,6 +1353,7 @@
                 ALOGE("%s: Failed to init audio route controls, aborting.",
                        __func__);
                 free(my_data);
+                free(snd_card_name);
                 return NULL;
             }
             adev->snd_card = snd_card_num;
@@ -1361,6 +1367,7 @@
     if (snd_card_num >= MAX_SND_CARD) {
         ALOGE("%s: Unable to find correct sound card, aborting.", __func__);
         free(my_data);
+        free(snd_card_name);
         return NULL;
     }
 
@@ -1559,6 +1566,7 @@
         strdup("SLIM_5_RX SampleRate");
 
     my_data->edid_info = NULL;
+    free(snd_card_name);
     return my_data;
 }
 
diff --git a/policy_hal/AudioPolicyManager.cpp b/policy_hal/AudioPolicyManager.cpp
index 7d3d82e..9fd6838 100644
--- a/policy_hal/AudioPolicyManager.cpp
+++ b/policy_hal/AudioPolicyManager.cpp
@@ -977,6 +977,7 @@
         // store time at which the stream was stopped - see isStreamActive()
         if (outputDesc->mRefCount[stream] == 0 || forceDeviceUpdate) {
             outputDesc->mStopTime[stream] = systemTime();
+            audio_devices_t prevDevice = outputDesc->device();
             audio_devices_t newDevice = getNewOutputDevice(outputDesc, false /*fromCache*/);
             // delay the device switch by twice the latency because stopOutput() is executed when
             // the track stop() command is received and at that time the audio track buffer can
@@ -995,10 +996,16 @@
                         outputDesc->sharesHwModuleWith(desc) &&
                         (newDevice != desc->device())) {
                         audio_devices_t dev = getNewOutputDevice(mOutputs.valueFor(curOutput), false /*fromCache*/);
+                        uint32_t delayMs;
+                        if (dev == prevDevice) {
+                            delayMs = 0;
+                        } else {
+                            delayMs = outputDesc->mLatency*2;
+                        }
                         setOutputDevice(desc,
                                     dev,
                                     true,
-                                    outputDesc->latency()*2);
+                                    delayMs);
                 }
             }
             // update the outputs if stopping one with a stream that can affect notification routing
diff --git a/post_proc/volume_listener.c b/post_proc/volume_listener.c
index 51f8803..d4f418a 100644
--- a/post_proc/volume_listener.c
+++ b/post_proc/volume_listener.c
@@ -344,7 +344,7 @@
     if (in_buffer->raw != out_buffer->raw) {
         memcpy(out_buffer->raw, in_buffer->raw, out_buffer->frameCount * 2 * sizeof(int16_t));
     } else {
-        ALOGW("%s: something wrong, didn't handle in_buffer and out_buffer same address case",
+        ALOGV("%s: something wrong, didn't handle in_buffer and out_buffer same address case",
               __func__);
     }
 
@@ -681,6 +681,11 @@
     bool recompute_flag = false;
     int active_stream_count = 0;
     ALOGV("%s context %p", __func__, handle);
+    if (recv_contex == NULL || recv_contex->desc == NULL) {
+        ALOGE("%s: Got invalid handle while release, DO NOTHING ", __func__);
+        return status;
+    }
+
     pthread_mutex_lock(&vol_listner_init_lock);
 
     // check if the handle/context provided is valid
@@ -690,13 +695,14 @@
             && (context->session_id == recv_contex->session_id)
             && (context->stream_type == recv_contex->stream_type)) {
             ALOGV("--- Found something to remove ---");
-            list_remove(&context->effect_list_node);
             PRINT_STREAM_TYPE(context->stream_type);
             if (context->dev_id && AUDIO_DEVICE_OUT_SPEAKER) {
                 recompute_flag = true;
             }
+            list_remove(&context->effect_list_node);
             free(context);
             status = 0;
+            break;
         } else {
             ++active_stream_count;
         }