diff --git a/src/include/sof/lib/notifier.h b/src/include/sof/lib/notifier.h
index 6c00a89b48b4..2f10b2d97aee 100644
--- a/src/include/sof/lib/notifier.h
+++ b/src/include/sof/lib/notifier.h
@@ -58,15 +58,43 @@ struct notify_data {
 
 struct notify **arch_notify_get(void);
 
-int notifier_register(void *receiver, void *caller, enum notify_id type,
-		      void (*cb)(void *arg, enum notify_id type, void *data),
+/** Register a callback to be run when event 'type' happens.
+ *
+ * The identifier for un-registration is the tuple (receiver_data,
+ * caller_id_filter, event_type), the callback argument is not part of
+ * it.
+ *
+ * caller_data argument from notifier_event()
+ *
+ * @param receiver_data private data passed to the callback.
+ * @param caller_id_filter optional, can be used to be notified only by
+ * some specific notifier_event() calls when not NULL.
+ * @param event_type list of callbacks to be added to
+ * @param callback callback function
+ * @param flags see NOTIFIER_FLAG_* above
+ */
+int notifier_register(void *receiver_data, void *caller_id_filter, enum notify_id event_type,
+		      void (*callback)(void *receiver_data, enum notify_id event_type,
+				       void *caller_data),
 		      uint32_t flags);
-void notifier_unregister(void *receiver, void *caller, enum notify_id type);
-void notifier_unregister_all(void *receiver, void *caller);
+
+/** Unregister all callbacks matching that arguments tuple. NULL acts
+ * as a wildcard.
+ */
+void notifier_unregister(void *receiver_data_filter, void *caller_id_filter, enum notify_id type);
+
+/** Unregister callbacks matching the arguments for every notify_id.
+ *  A NULL parameter acts as a wildcard.
+ */
+void notifier_unregister_all(void *receiver_data_filter, void *caller_id_filter);
 
 void notifier_notify_remote(void);
-void notifier_event(const void *caller, enum notify_id type, uint32_t core_mask,
-		    void *data, uint32_t data_size);
+
+/* data_size is required to manage cache coherency for notifications
+ * across cores.
+ */
+void notifier_event(const void *caller_id, enum notify_id event_type, uint32_t core_mask,
+		    void *caller_data, uint32_t data_size);
 
 void init_system_notify(struct sof *sof);
 
diff --git a/zephyr/wrapper.c b/zephyr/wrapper.c
index f978f5d59b19..9ab76b66f1b0 100644
--- a/zephyr/wrapper.c
+++ b/zephyr/wrapper.c
@@ -406,6 +406,15 @@ unsigned int _xtos_ints_off(unsigned int mask)
 	return 0;
 }
 
+void ipc_send_queued_msg(void);
+
+static void ipc_send_queued_callback(void *private_data, enum notify_id event_type,
+				     void *caller_data)
+{
+	if (!ipc_get()->pm_prepare_D3)
+		ipc_send_queued_msg();
+}
+
 /*
  * Audio components.
  *
@@ -528,6 +537,10 @@ int task_main_start(struct sof *sof)
 	/* init pipeline position offsets */
 	pipeline_posn_init(sof);
 
+	(void)notifier_register(NULL, scheduler_get_data(SOF_SCHEDULE_LL_TIMER),
+				NOTIFIER_ID_LL_POST_RUN,
+				ipc_send_queued_callback, 0);
+
 	/* let host know DSP boot is complete */
 	ret = platform_boot_complete(0);