diff --git a/include/hardware/audio.h b/include/hardware/audio.h
index 59fb9a3..763ca58 100644
--- a/include/hardware/audio.h
+++ b/include/hardware/audio.h
@@ -124,6 +124,8 @@
 #define AUDIO_PARAMETER_STREAM_INPUT_SOURCE "input_source"   /* audio_source_t */
 #define AUDIO_PARAMETER_STREAM_SAMPLING_RATE "sampling_rate" /* uint32_t */
 
+#define AUDIO_PARAMETER_DEVICE_DISCONNECT "disconnect"      /* audio_devices_t */
+
 /* Query supported formats. The response is a '|' separated list of strings from
  * audio_format_t enum e.g: "sup_formats=AUDIO_FORMAT_PCM_16_BIT" */
 #define AUDIO_PARAMETER_STREAM_SUP_FORMATS "sup_formats"
diff --git a/include/hardware/sensors.h b/include/hardware/sensors.h
index 495828a..a44c155 100644
--- a/include/hardware/sensors.h
+++ b/include/hardware/sensors.h
@@ -495,9 +495,11 @@
  *
  *  Because this sensor is on-change, events must be generated when and only
  *  when heart_rate.bpm or heart_rate.status have changed since the last
- *  event. The event should be generated no faster than every period_ns passed
- *  to setDelay() or to batch(). See the definition of the on-change reporting
- *  mode for more information.
+ *  event. In particular, upon the first activation, unless the device is known
+ *  to not be on the body, the status field of the first event must be set to
+ *  SENSOR_STATUS_UNRELIABLE. The event should be generated no faster than every
+ *  period_ns passed to setDelay() or to batch().
+ *  See the definition of the on-change reporting mode for more information.
  *
  *  sensor_t.requiredPermission must be set to SENSOR_PERMISSION_BODY_SENSORS.
  *
diff --git a/modules/usbaudio/alsa_device_profile.c b/modules/usbaudio/alsa_device_profile.c
index f214eab..c7df00c 100644
--- a/modules/usbaudio/alsa_device_profile.c
+++ b/modules/usbaudio/alsa_device_profile.c
@@ -92,6 +92,14 @@
     return profile->is_valid;
 }
 
+bool profile_is_cached_for(alsa_device_profile* profile, int card, int device) {
+    return card == profile->card && device == profile->device;
+}
+
+void profile_decache(alsa_device_profile* profile) {
+    profile->card = profile->device = -1;
+}
+
 /*
  * Returns the supplied value rounded up to the next even multiple of 16
  */
@@ -267,19 +275,28 @@
 
 static unsigned profile_enum_channel_counts(alsa_device_profile* profile, unsigned min, unsigned max)
 {
-    static const unsigned std_channel_counts[] = {8, 4, 2, 1};
+    // TODO: Don't return MONO even if the device supports it. This causes problems
+    // in AudioPolicyManager. Revisit.
+    static const unsigned std_out_channel_counts[] = {8, 4, 2/*, 1*/};
+    static const unsigned std_in_channel_counts[] = {8, 4, 2, 1};
+
+    unsigned * channel_counts =
+        profile->direction == PCM_OUT ? std_out_channel_counts : std_in_channel_counts;
+    unsigned num_channel_counts =
+        profile->direction == PCM_OUT
+            ? ARRAY_SIZE(std_out_channel_counts) : ARRAY_SIZE(std_in_channel_counts);
 
     unsigned num_counts = 0;
     unsigned index;
     /* TODO write a profile_test_channel_count() */
     /* Ensure there is at least one invalid channel count to terminate the channel counts array */
-    for (index = 0; index < ARRAY_SIZE(std_channel_counts) &&
+    for (index = 0; index < num_channel_counts &&
                     num_counts < ARRAY_SIZE(profile->channel_counts) - 1;
          index++) {
         /* TODO Do we want a channel counts test? */
-        if (std_channel_counts[index] >= min && std_channel_counts[index] <= max /* &&
-         profile_test_channel_count(profile, std_channel_counts[index])*/) {
-            profile->channel_counts[num_counts++] = std_channel_counts[index];
+        if (channel_counts[index] >= min && channel_counts[index] <= max /* &&
+            profile_test_channel_count(profile, channel_counts[index])*/) {
+            profile->channel_counts[num_counts++] = channel_counts[index];
         }
     }
 
diff --git a/modules/usbaudio/alsa_device_profile.h b/modules/usbaudio/alsa_device_profile.h
index b75e1dc..2c0da39 100644
--- a/modules/usbaudio/alsa_device_profile.h
+++ b/modules/usbaudio/alsa_device_profile.h
@@ -61,6 +61,8 @@
 void profile_init(alsa_device_profile* profile, int direction);
 bool profile_is_initialized(alsa_device_profile* profile);
 bool profile_is_valid(alsa_device_profile* profile);
+bool profile_is_cached_for(alsa_device_profile* profile, int card, int device);
+void profile_decache(alsa_device_profile* profile);
 
 bool profile_read_device_info(alsa_device_profile* profile);
 
diff --git a/modules/usbaudio/alsa_device_proxy.c b/modules/usbaudio/alsa_device_proxy.c
index e15f093..081c05b 100644
--- a/modules/usbaudio/alsa_device_proxy.c
+++ b/modules/usbaudio/alsa_device_proxy.c
@@ -27,20 +27,6 @@
 #define DEFAULT_PERIOD_SIZE     1024
 #define DEFAULT_PERIOD_COUNT    2
 
-//void proxy_init(alsa_device_proxy * proxy)
-//{
-//    proxy->profile = NULL;
-//
-//    proxy->alsa_config.format = DEFAULT_SAMPLE_FORMAT;
-//    proxy->alsa_config.rate = DEFAULT_SAMPLE_RATE;
-//    proxy->alsa_config.channels = DEFAULT_CHANNEL_COUNT;
-//
-//    proxy->alsa_config.period_size = DEFAULT_PERIOD_SIZE;
-//    proxy->alsa_config.period_count = DEFAULT_PERIOD_COUNT;
-//
-//    proxy->pcm = NULL;
-//}
-
 void proxy_prepare(alsa_device_proxy * proxy, alsa_device_profile* profile,
                    struct pcm_config * config)
 {
@@ -79,7 +65,6 @@
 int proxy_open(alsa_device_proxy * proxy)
 {
     alsa_device_profile* profile = proxy->profile;
-
     ALOGV("proxy_open(card:%d device:%d %s)", profile->card, profile->device,
           profile->direction == PCM_OUT ? "PCM_OUT" : "PCM_IN");
 
@@ -103,8 +88,12 @@
 
 void proxy_close(alsa_device_proxy * proxy)
 {
-    pcm_close(proxy->pcm);
-    proxy->pcm = NULL;
+    ALOGV("proxy_close() [pcm:%p]", proxy->pcm);
+
+    if (proxy->pcm != NULL) {
+        pcm_close(proxy->pcm);
+        proxy->pcm = NULL;
+    }
 }
 
 /*
diff --git a/modules/usbaudio/audio_hw.c b/modules/usbaudio/audio_hw.c
index 7e65ab5..caddf97 100644
--- a/modules/usbaudio/audio_hw.c
+++ b/modules/usbaudio/audio_hw.c
@@ -253,7 +253,6 @@
     const struct stream_out* out = (const struct stream_out*)stream;
     size_t buffer_size =
         proxy_get_period_size(&out->proxy) * audio_stream_out_frame_size(&(out->stream));
-    ALOGV("out_get_buffer_size()  = %zu", buffer_size);
     return buffer_size;
 }
 
@@ -271,7 +270,6 @@
      */
     alsa_device_proxy * proxy = &((struct stream_out*)stream)->proxy;
     audio_format_t format = audio_format_from_pcm_format(proxy_get_format(proxy));
-    ALOGV("out_get_format() = %d", format);
     return format;
 }
 
@@ -328,7 +326,7 @@
     if (param_val >= 0)
         device = atoi(value);
 
-    if (card >= 0 && device >= 0) {
+    if (card >= 0 && device >= 0 && !profile_is_cached_for(out->profile, card, device)) {
         /* cannot read pcm device info if playback is active */
         if (!out->standby)
             ret_value = -ENOSYS;
@@ -344,6 +342,7 @@
             }
         }
     }
+
     pthread_mutex_unlock(&out->lock);
     pthread_mutex_unlock(&out->dev->lock);
     str_parms_destroy(parms);
@@ -402,7 +401,6 @@
     }
     pthread_mutex_unlock(&out->dev->lock);
 
-
     alsa_device_proxy* proxy = &out->proxy;
     const void * write_buff = buffer;
     int num_write_buff_bytes = bytes;
@@ -517,6 +515,7 @@
 
     // build this to hand to the alsa_device_proxy
     struct pcm_config proxy_config;
+    memset(&proxy_config, 0, sizeof(proxy_config));
 
     int ret = 0;
 
@@ -705,7 +704,7 @@
     pthread_mutex_lock(&in->dev->lock);
     pthread_mutex_lock(&in->lock);
 
-    /* Card/Device */
+    /* Device Connection Message ("card=1,device=0") */
     param_val = str_parms_get_str(parms, "card", value, sizeof(value));
     if (param_val >= 0)
         card = atoi(value);
@@ -714,7 +713,7 @@
     if (param_val >= 0)
         device = atoi(value);
 
-    if (card >= 0 && device >= 0) {
+    if (card >= 0 && device >= 0 && !profile_is_cached_for(in->profile, card, device)) {
         /* cannot read pcm device info if playback is active */
         if (!in->standby)
             ret_value = -ENOSYS;
@@ -729,7 +728,7 @@
                 in->profile->device = saved_device;
             }
         }
-     }
+    }
 
     pthread_mutex_unlock(&in->lock);
     pthread_mutex_unlock(&in->dev->lock);
@@ -924,6 +923,7 @@
     in->profile = &in->dev->in_profile;
 
     struct pcm_config proxy_config;
+    memset(&proxy_config, 0, sizeof(proxy_config));
 
     /* Rate */
     if (config->sample_rate == 0) {
@@ -996,6 +996,41 @@
  */
 static int adev_set_parameters(struct audio_hw_device *dev, const char *kvpairs)
 {
+    ALOGV("audio_hw:usb adev_set_parameters(%s)", kvpairs);
+
+    struct audio_device * adev = (struct audio_device *)dev;
+
+    char value[32];
+    int param_val;
+
+    struct str_parms * parms = str_parms_create_str(kvpairs);
+
+    /* Check for the "disconnect" message */
+    param_val = str_parms_get_str(parms, "disconnect", value, sizeof(value));
+    if (param_val >= 0) {
+        audio_devices_t device = (audio_devices_t)atoi(value);
+
+        param_val = str_parms_get_str(parms, "card", value, sizeof(value));
+        int alsa_card = param_val >= 0 ? atoi(value) : -1;
+
+        param_val = str_parms_get_str(parms, "device", value, sizeof(value));
+        int alsa_device = param_val >= 0 ? atoi(value) : -1;
+
+        if (alsa_card >= 0 && alsa_device >= 0) {
+            /* "decache" the profile */
+            pthread_mutex_lock(&adev->lock);
+            if (device == AUDIO_DEVICE_OUT_USB_DEVICE &&
+                profile_is_cached_for(&adev->out_profile, alsa_card, alsa_device)) {
+                profile_decache(&adev->out_profile);
+            }
+            if (device == AUDIO_DEVICE_IN_USB_DEVICE &&
+                profile_is_cached_for(&adev->in_profile, alsa_card, alsa_device)) {
+                profile_decache(&adev->in_profile);
+            }
+            pthread_mutex_unlock(&adev->lock);
+        }
+    }
+
     return 0;
 }