diff --git a/drivers/serial/serial.c b/drivers/serial/serial.c
index ee7fc7e253..5d746b83f4 100644
--- a/drivers/serial/serial.c
+++ b/drivers/serial/serial.c
@@ -112,6 +112,9 @@ static int     uart_ioctl(FAR struct file *filep,
                           int cmd, unsigned long arg);
 static int     uart_poll(FAR struct file *filep,
                          FAR struct pollfd *fds, bool setup);
+#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
+static int     uart_unlink(FAR struct inode *inode);
+#endif
 
 /****************************************************************************
  * Public Function Prototypes
@@ -129,15 +132,18 @@ int CONFIG_TTY_LAUNCH_ENTRYPOINT(int argc, char *argv[]);
 
 static const struct file_operations g_serialops =
 {
-  uart_open,  /* open */
-  uart_close, /* close */
-  uart_read,  /* read */
-  uart_write, /* write */
-  NULL,       /* seek */
-  uart_ioctl, /* ioctl */
-  NULL,       /* mmap */
-  NULL,       /* truncate */
-  uart_poll   /* poll */
+  uart_open,    /* open */
+  uart_close,   /* close */
+  uart_read,    /* read */
+  uart_write,   /* write */
+  NULL,         /* seek */
+  uart_ioctl,   /* ioctl */
+  NULL,         /* mmap */
+  NULL,         /* truncate */
+  uart_poll     /* poll */
+#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
+  , uart_unlink /* unlink */
+#endif
 };
 
 #ifdef CONFIG_TTY_LAUNCH
@@ -725,6 +731,20 @@ static int uart_close(FAR struct file *filep)
    */
 
   uart_reset_sem(dev);
+
+  if (dev->unlinked)
+    {
+      nxmutex_unlock(&dev->closelock);
+      nxmutex_destroy(&dev->xmit.lock);
+      nxmutex_destroy(&dev->recv.lock);
+      nxmutex_destroy(&dev->closelock);
+      nxmutex_destroy(&dev->polllock);
+      nxsem_destroy(&dev->xmitsem);
+      nxsem_destroy(&dev->recvsem);
+      uart_release(dev);
+      return OK;
+    }
+
   nxmutex_unlock(&dev->closelock);
   return OK;
 }
@@ -1703,6 +1723,46 @@ errout:
   return ret;
 }
 
+/****************************************************************************
+ * Name: uart_unlink
+ ****************************************************************************/
+
+#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
+static int uart_unlink(FAR struct inode *inode)
+{
+  FAR uart_dev_t *dev;
+  int ret;
+
+  DEBUGASSERT(inode->i_private != NULL);
+
+  dev = inode->i_private;
+  ret = nxmutex_lock(&dev->closelock);
+  if (ret < 0)
+    {
+      /* A signal received while waiting for the last close operation. */
+
+      return ret;
+    }
+
+  if (dev->open_count <= 0)
+    {
+      nxmutex_unlock(&dev->closelock);
+      nxmutex_destroy(&dev->xmit.lock);
+      nxmutex_destroy(&dev->recv.lock);
+      nxmutex_destroy(&dev->closelock);
+      nxmutex_destroy(&dev->polllock);
+      nxsem_destroy(&dev->xmitsem);
+      nxsem_destroy(&dev->recvsem);
+      uart_release(dev);
+      return OK;
+    }
+
+  dev->unlinked = true;
+  nxmutex_unlock(&dev->closelock);
+  return OK;
+}
+#endif
+
 /****************************************************************************
  * Name: uart_nxsched_foreach_cb
  ****************************************************************************/
diff --git a/drivers/usbdev/cdcacm.c b/drivers/usbdev/cdcacm.c
index ea439d8ec7..dcf9cbf3ca 100644
--- a/drivers/usbdev/cdcacm.c
+++ b/drivers/usbdev/cdcacm.c
@@ -222,6 +222,7 @@ static bool    cdcuart_rxflowcontrol(FAR struct uart_dev_s *dev,
 #endif
 static void    cdcuart_txint(FAR struct uart_dev_s *dev, bool enable);
 static bool    cdcuart_txempty(FAR struct uart_dev_s *dev);
+static int     cdcuart_release(FAR struct uart_dev_s *dev);
 
 /****************************************************************************
  * Private Data
@@ -272,7 +273,8 @@ static const struct uart_ops_s g_uartops =
   NULL,                  /* send */
   cdcuart_txint,         /* txinit */
   NULL,                  /* txready */
-  cdcuart_txempty        /* txempty */
+  cdcuart_txempty,       /* txempty */
+  cdcuart_release        /* release */
 };
 
 /****************************************************************************
@@ -2800,6 +2802,28 @@ static bool cdcuart_txempty(FAR struct uart_dev_s *dev)
   return priv->nwrq >= CONFIG_CDCACM_NWRREQS;
 }
 
+/****************************************************************************
+ * Name: cdcuart_release
+ *
+ * Description:
+ *   This is called to release some resource about the device when device
+ *   was close and unregistered.
+ *
+ ****************************************************************************/
+
+static int cdcuart_release(FAR struct uart_dev_s *dev)
+{
+  FAR struct cdcacm_dev_s *priv = (FAR struct cdcacm_dev_s *)dev->priv;
+
+  usbtrace(CDCACM_CLASSAPI_RELEASE, 0);
+
+  /* And free the memory resources. */
+
+  wd_cancel(&priv->rxfailsafe);
+  kmm_free(priv);
+  return OK;
+}
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
diff --git a/drivers/usbdev/cdcacm.h b/drivers/usbdev/cdcacm.h
index 6e97148ef8..00dfe6b581 100644
--- a/drivers/usbdev/cdcacm.h
+++ b/drivers/usbdev/cdcacm.h
@@ -181,6 +181,7 @@
 #define CDCACM_CLASSAPI_TXREADY     TRACE_EVENT(TRACE_CLASSAPI_ID, USBSER_TRACECLASSAPI_TXREADY)
 #define CDCACM_CLASSAPI_TXEMPTY     TRACE_EVENT(TRACE_CLASSAPI_ID, USBSER_TRACECLASSAPI_TXEMPTY)
 #define CDCACM_CLASSAPI_FLOWCONTROL TRACE_EVENT(TRACE_CLASSAPI_ID, USBSER_TRACECLASSAPI_FLOWCONTROL)
+#define CDCACM_CLASSAPI_RELEASE     TRACE_EVENT(TRACE_CLASSAPI_ID, USBSER_TRACECLASSAPI_RELEASE)
 
 /****************************************************************************
  * Public Types
diff --git a/include/nuttx/serial/serial.h b/include/nuttx/serial/serial.h
index aa7f7ff4de..13e5fc28c3 100644
--- a/include/nuttx/serial/serial.h
+++ b/include/nuttx/serial/serial.h
@@ -88,6 +88,9 @@
 #define uart_send(dev,ch)        dev->ops->send(dev,ch)
 #define uart_receive(dev,s)      dev->ops->receive(dev,s)
 
+#define uart_release(dev)      \
+  ((dev)->ops->release ? (dev)->ops->release(dev) : -ENOSYS)
+
 #ifdef CONFIG_SERIAL_TXDMA
 #define uart_dmasend(dev)      \
   ((dev)->ops->dmasend ? (dev)->ops->dmasend(dev) : -ENOSYS)
@@ -254,6 +257,12 @@ struct uart_ops_s
    */
 
   CODE bool (*txempty)(FAR struct uart_dev_s *dev);
+
+  /* Call to release some resource about the device when device was close
+   * and unregistered.
+   */
+
+  CODE int (*release)(FAR struct uart_dev_s *dev);
 };
 
 /* This is the device structure used by the driver.  The caller of
@@ -276,6 +285,7 @@ struct uart_dev_s
   volatile bool        disconnected; /* true: Removable device is not connected */
 #endif
   bool                 isconsole;    /* true: This is the serial console */
+  bool                 unlinked;     /* true: This device driver has been unlinked. */
 
 #if defined(CONFIG_TTY_SIGINT) || defined(CONFIG_TTY_SIGTSTP) || \
     defined(CONFIG_TTY_FORCE_PANIC) || defined(CONFIG_TTY_LAUNCH)
diff --git a/include/nuttx/usb/usbdev_trace.h b/include/nuttx/usb/usbdev_trace.h
index 9246c44963..0993af5a0d 100644
--- a/include/nuttx/usb/usbdev_trace.h
+++ b/include/nuttx/usb/usbdev_trace.h
@@ -187,6 +187,7 @@
 #define USBSER_TRACECLASSAPI_TXREADY                 0x000b
 #define USBSER_TRACECLASSAPI_TXEMPTY                 0x000c
 #define USBSER_TRACECLASSAPI_FLOWCONTROL             0x000d
+#define USBSER_TRACECLASSAPI_RELEASE                 0x000e
 
 /* Values of the class error ID used by the USB serial driver */