diff --git a/hal/audio_extn/sndmonitor.c b/hal/audio_extn/sndmonitor.c
index 86a5b93..58ab43d 100644
--- a/hal/audio_extn/sndmonitor.c
+++ b/hal/audio_extn/sndmonitor.c
@@ -582,8 +582,12 @@
 
     write(sndmonitor.intpipe[1], "Q", 1);
     pthread_join(sndmonitor.monitor_thread, (void **) NULL);
-    free_sndcards();
     free_dev_events();
+    listeners_deinit();
+    free_sndcards();
+    close(sndmonitor.intpipe[0]);
+    close(sndmonitor.intpipe[1]);
+
     sndmonitor.initcheck = 0;
     return 0;
 }
@@ -597,13 +601,13 @@
     sndmonitor.initcheck = false;
 
     if (pipe(sndmonitor.intpipe) < 0)
-        return -ENODEV;
+        goto pipe_error;
 
     if (enum_sndcards() < 0)
-        return -ENODEV;
+        goto enum_sncards_error;
 
     if (listeners_init() < 0)
-        return -ENODEV;
+        goto listeners_error;
 
 #ifdef MONITOR_DEVICE_EVENTS
     enum_dev_events(); // failure here isn't fatal
@@ -614,14 +618,20 @@
                              monitor_thread_loop, NULL);
 
     if (ret) {
-        free_sndcards();
-        free_dev_events();
-        close(sndmonitor.intpipe[0]);
-        close(sndmonitor.intpipe[1]);
-        return -ENODEV;
+        goto monitor_thread_create_error;
     }
     sndmonitor.initcheck = true;
     return 0;
+
+monitor_thread_create_error:
+    listeners_deinit();
+listeners_error:
+    free_sndcards();
+enum_sncards_error:
+    close(sndmonitor.intpipe[0]);
+    close(sndmonitor.intpipe[1]);
+pipe_error:
+    return -ENODEV;
 }
 
 int audio_extn_snd_mon_register_listener(void *stream, snd_mon_cb cb)
diff --git a/hal/audio_hw.c b/hal/audio_hw.c
index 1f762e9..6ca763e 100644
--- a/hal/audio_hw.c
+++ b/hal/audio_hw.c
@@ -33,6 +33,7 @@
 #include <dlfcn.h>
 #include <sys/resource.h>
 #include <sys/prctl.h>
+#include <limits.h>
 
 #include <cutils/log.h>
 #include <cutils/trace.h>
@@ -2093,7 +2094,7 @@
         str_parms_add_str(reply, AUDIO_PARAMETER_STREAM_SUP_CHANNELS, value);
         str = str_parms_to_str(reply);
     } else {
-        str = strdup(keys);
+        str = strdup("");
     }
     str_parms_destroy(query);
     str_parms_destroy(reply);
@@ -2362,7 +2363,7 @@
         pthread_mutex_unlock(&out->lock);
         return 0;
     } else
-        return -EINVAL;
+        return -ENODATA;
 }
 
 static int out_add_audio_effect(const struct audio_stream *stream __unused,
@@ -2380,14 +2381,14 @@
 static int out_get_next_write_timestamp(const struct audio_stream_out *stream __unused,
                                         int64_t *timestamp __unused)
 {
-    return -EINVAL;
+    return -ENOSYS;
 }
 
 static int out_get_presentation_position(const struct audio_stream_out *stream,
                                    uint64_t *frames, struct timespec *timestamp)
 {
     struct stream_out *out = (struct stream_out *)stream;
-    int ret = -EINVAL;
+    int ret = -ENODATA;
     unsigned long dsp_frames;
 
     lock_output_stream(out);
@@ -2812,7 +2813,7 @@
 
 static int in_set_gain(struct audio_stream_in *stream __unused, float gain __unused)
 {
-    return 0;
+    return -ENOSYS;
 }
 
 static void in_snd_mon_cb(void * stream, struct str_parms * parms)
@@ -4054,10 +4055,11 @@
     if (!adev)
         return 0;
 
+    audio_extn_snd_mon_unregister_listener(adev);
     audio_extn_snd_mon_deinit();
+
     audio_extn_tfa_98xx_deinit();
 
-    audio_extn_snd_mon_unregister_listener(adev);
     pthread_mutex_lock(&adev_init_lock);
 
     if ((--audio_device_ref_count) == 0) {
diff --git a/hal/msm8916/platform.c b/hal/msm8916/platform.c
index 65600ee..2fe6168 100644
--- a/hal/msm8916/platform.c
+++ b/hal/msm8916/platform.c
@@ -1054,6 +1054,7 @@
         free(info_item);
     }
 
+    mixer_close(my_data->adev->mixer);
     free(platform);
 }
 
diff --git a/hal/msm8974/platform.c b/hal/msm8974/platform.c
index 7bbf168..0f3bcf0 100644
--- a/hal/msm8974/platform.c
+++ b/hal/msm8974/platform.c
@@ -1483,6 +1483,7 @@
         free(info_item);
     }
 
+    mixer_close(my_data->adev->mixer);
     free(platform);
 
     /* deinit usb */