diff --git a/class/cdc/usbh_cdc_acm.c b/class/cdc/usbh_cdc_acm.c
index bb01e88c..77300a9c 100644
--- a/class/cdc/usbh_cdc_acm.c
+++ b/class/cdc/usbh_cdc_acm.c
@@ -12,50 +12,27 @@ static uint32_t g_devinuse = 0;
 
 USB_NOCACHE_RAM_SECTION USB_MEM_ALIGNX struct cdc_line_coding g_cdc_line_coding;
 
-/****************************************************************************
- * Name: usbh_cdc_acm_devno_alloc
- *
- * Description:
- *   Allocate a unique /dev/ttyACM[n] minor number in the range 0-31.
- *
- ****************************************************************************/
-
 static int usbh_cdc_acm_devno_alloc(struct usbh_cdc_acm *cdc_acm_class)
 {
-    size_t flags;
     int devno;
 
-    flags = usb_osal_enter_critical_section();
     for (devno = 0; devno < 32; devno++) {
         uint32_t bitno = 1 << devno;
         if ((g_devinuse & bitno) == 0) {
             g_devinuse |= bitno;
             cdc_acm_class->minor = devno;
-            usb_osal_leave_critical_section(flags);
             return 0;
         }
     }
-
-    usb_osal_leave_critical_section(flags);
     return -EMFILE;
 }
 
-/****************************************************************************
- * Name: usbh_cdc_acm_devno_free
- *
- * Description:
- *   Free a /dev/ttyACM[n] minor number so that it can be used.
- *
- ****************************************************************************/
-
 static void usbh_cdc_acm_devno_free(struct usbh_cdc_acm *cdc_acm_class)
 {
     int devno = cdc_acm_class->minor;
 
     if (devno >= 0 && devno < 32) {
-        size_t flags = usb_osal_enter_critical_section();
         g_devinuse &= ~(1 << devno);
-        usb_osal_leave_critical_section(flags);
     }
 }
 
diff --git a/class/hid/usbh_hid.c b/class/hid/usbh_hid.c
index 6794a307..9b726007 100644
--- a/class/hid/usbh_hid.c
+++ b/class/hid/usbh_hid.c
@@ -12,50 +12,28 @@ static uint32_t g_devinuse = 0;
 
 USB_NOCACHE_RAM_SECTION USB_MEM_ALIGNX uint8_t g_hid_buf[128];
 
-/****************************************************************************
- * Name: usbh_hid_devno_alloc
- *
- * Description:
- *   Allocate a unique /dev/input[n] minor number in the range 0-31.
- *
- ****************************************************************************/
-
 static int usbh_hid_devno_alloc(struct usbh_hid *hid_class)
 {
-    size_t flags;
     int devno;
 
-    flags = usb_osal_enter_critical_section();
     for (devno = 0; devno < 32; devno++) {
         uint32_t bitno = 1 << devno;
         if ((g_devinuse & bitno) == 0) {
             g_devinuse |= bitno;
             hid_class->minor = devno;
-            usb_osal_leave_critical_section(flags);
             return 0;
         }
     }
 
-    usb_osal_leave_critical_section(flags);
     return -EMFILE;
 }
 
-/****************************************************************************
- * Name: usbh_hid_devno_free
- *
- * Description:
- *   Free a /dev/input[n] minor number so that it can be used.
- *
- ****************************************************************************/
-
 static void usbh_hid_devno_free(struct usbh_hid *hid_class)
 {
     int devno = hid_class->minor;
 
     if (devno >= 0 && devno < 32) {
-        size_t flags = usb_osal_enter_critical_section();
         g_devinuse &= ~(1 << devno);
-        usb_osal_leave_critical_section(flags);
     }
 }
 
@@ -118,9 +96,9 @@ int usbh_hid_set_protocol(struct usbh_hid *hid_class, uint8_t protocol)
     setup->bRequest = HID_REQUEST_SET_PROTOCOL;
     setup->wValue = protocol;
     setup->wIndex = 0;
-    setup->wLength = 0;   
+    setup->wLength = 0;
 
-    return usbh_control_transfer(hid_class->hport->ep0, setup, NULL);     
+    return usbh_control_transfer(hid_class->hport->ep0, setup, NULL);
 }
 
 int usbh_hid_connect(struct usbh_hubport *hport, uint8_t intf)
diff --git a/class/hub/usbh_hub.c b/class/hub/usbh_hub.c
index e262f872..4796bf45 100644
--- a/class/hub/usbh_hub.c
+++ b/class/hub/usbh_hub.c
@@ -34,14 +34,6 @@ extern int usbh_enumerate(struct usbh_hubport *hport);
 
 static const char *speed_table[] = { "error-speed", "low-speed", "full-speed", "high-speed", "wireless-speed", "super-speed", "superplus-speed" };
 
-/****************************************************************************
- * Name: usbh_hub_devno_alloc
- *
- * Description:
- *   Allocate a unique /dev/hub[n] minor number in the range 2-31.
- *
- ****************************************************************************/
-
 static int usbh_hub_devno_alloc(void)
 {
     int devno;
@@ -57,14 +49,6 @@ static int usbh_hub_devno_alloc(void)
     return -EMFILE;
 }
 
-/****************************************************************************
- * Name: usbh_hub_devno_free
- *
- * Description:
- *   Free a /dev/hub[n] minor number so that it can be used.
- *
- ****************************************************************************/
-
 static void usbh_hub_devno_free(struct usbh_hub *hub)
 {
     int devno = hub->index;
diff --git a/class/msc/usbh_msc.c b/class/msc/usbh_msc.c
index d85fbf8c..550b0c25 100644
--- a/class/msc/usbh_msc.c
+++ b/class/msc/usbh_msc.c
@@ -13,50 +13,28 @@ static uint32_t g_devinuse = 0;
 
 USB_NOCACHE_RAM_SECTION USB_MEM_ALIGNX uint8_t g_msc_buf[32];
 
-/****************************************************************************
- * Name: usbh_msc_devno_alloc
- *
- * Description:
- *   Allocate a unique /dev/sd[n] minor number in the range 0-31.
- *
- ****************************************************************************/
-
 static int usbh_msc_devno_alloc(struct usbh_msc *msc_class)
 {
-    size_t flags;
     int devno;
 
-    flags = usb_osal_enter_critical_section();
     for (devno = 0; devno < 26; devno++) {
         uint32_t bitno = 1 << devno;
         if ((g_devinuse & bitno) == 0) {
             g_devinuse |= bitno;
             msc_class->sdchar = 'a' + devno;
-            usb_osal_leave_critical_section(flags);
             return 0;
         }
     }
 
-    usb_osal_leave_critical_section(flags);
     return -EMFILE;
 }
 
-/****************************************************************************
- * Name: usbh_msc_devno_free
- *
- * Description:
- *   Free a /dev/sd[n] minor number so that it can be used.
- *
- ****************************************************************************/
-
 static void usbh_msc_devno_free(struct usbh_msc *msc_class)
 {
     int devno = msc_class->sdchar - 'a';
 
     if (devno >= 0 && devno < 26) {
-        size_t flags = usb_osal_enter_critical_section();
         g_devinuse &= ~(1 << devno);
-        usb_osal_leave_critical_section(flags);
     }
 }
 
diff --git a/class/video/usbh_video.c b/class/video/usbh_video.c
index f7e9e510..14fd3786 100644
--- a/class/video/usbh_video.c
+++ b/class/video/usbh_video.c
@@ -70,50 +70,28 @@ static void yuyv2rgb565(void *input, void *output, uint32_t len)
     }
 }
 
-/****************************************************************************
- * Name: usbh_video_devno_alloc
- *
- * Description:
- *   Allocate a unique /dev/video[n] minor number in the range 0-31.
- *
- ****************************************************************************/
-
 static int usbh_video_devno_alloc(struct usbh_video *video_class)
 {
-    size_t flags;
     int devno;
 
-    flags = usb_osal_enter_critical_section();
     for (devno = 0; devno < 32; devno++) {
         uint32_t bitno = 1 << devno;
         if ((g_devinuse & bitno) == 0) {
             g_devinuse |= bitno;
             video_class->minor = devno;
-            usb_osal_leave_critical_section(flags);
             return 0;
         }
     }
 
-    usb_osal_leave_critical_section(flags);
     return -EMFILE;
 }
 
-/****************************************************************************
- * Name: usbh_video_devno_free
- *
- * Description:
- *   Free a /dev/video[n] minor number so that it can be used.
- *
- ****************************************************************************/
-
 static void usbh_video_devno_free(struct usbh_video *video_class)
 {
     int devno = video_class->minor;
 
     if (devno >= 0 && devno < 32) {
-        size_t flags = usb_osal_enter_critical_section();
         g_devinuse &= ~(1 << devno);
-        usb_osal_leave_critical_section(flags);
     }
 }