diff --git a/hw/bsp/stm32f407g_disc1/board.mk b/hw/bsp/stm32f407g_disc1/board.mk
index e20c0cb04..cbd6005dc 100644
--- a/hw/bsp/stm32f407g_disc1/board.mk
+++ b/hw/bsp/stm32f407g_disc1/board.mk
@@ -41,6 +41,7 @@ else
   endif
 endif
 
-# flash target using on-board stlink
+# flash target using on-board stlink or jlink
 flash: $(BUILD)/$(BOARD)-firmware.elf
 	$(STM32Prog) --connect port=swd --write $< --go
+	#JLinkExe 
\ No newline at end of file
diff --git a/hw/bsp/stm32f407g_disc1/board_stm32f407g_disc1.c b/hw/bsp/stm32f407g_disc1/board_stm32f407g_disc1.c
index ea9c779d5..fc872e838 100644
--- a/hw/bsp/stm32f407g_disc1/board_stm32f407g_disc1.c
+++ b/hw/bsp/stm32f407g_disc1/board_stm32f407g_disc1.c
@@ -45,8 +45,6 @@
 //--------------------------------------------------------------------+
 // MACRO TYPEDEF CONSTANT ENUM DECLARATION
 //--------------------------------------------------------------------+
-#define LED_STATE_ON  1
-
 void board_init(void)
 {
   // Init the LED on PD14
diff --git a/src/portable/st/stm32f4/dcd_stm32f4.c b/src/portable/st/stm32f4/dcd_stm32f4.c
index be5a99d08..e3b7b2db4 100644
--- a/src/portable/st/stm32f4/dcd_stm32f4.c
+++ b/src/portable/st/stm32f4/dcd_stm32f4.c
@@ -310,36 +310,46 @@ void dcd_edpt_stall (uint8_t rhport, uint8_t ep_addr)
   uint8_t const dir   = tu_edpt_dir(ep_addr);
 
   if(dir == TUSB_DIR_IN) {
-    // Stop transmitting packets and NAK IN xfers.
-    in_ep[epnum].DIEPCTL |= USB_OTG_DIEPCTL_SNAK;
-    while((in_ep[epnum].DIEPINT & USB_OTG_DIEPINT_INEPNE) == 0);
+    // Only disable currently enabled non-control endpoint
+    if ( (epnum == 0) || !(in_ep[epnum].DIEPCTL & USB_OTG_DIEPCTL_EPENA) ){
+      in_ep[epnum].DIEPCTL |= (USB_OTG_DIEPCTL_SNAK | USB_OTG_DIEPCTL_STALL);
+    }else {
+      // Stop transmitting packets and NAK IN xfers.
+      in_ep[epnum].DIEPCTL |= USB_OTG_DIEPCTL_SNAK;
+      while((in_ep[epnum].DIEPINT & USB_OTG_DIEPINT_INEPNE) == 0);
 
-    // Disable the endpoint. Note that both SNAK and STALL are set here.
-    in_ep[epnum].DIEPCTL |= (USB_OTG_DIEPCTL_SNAK | USB_OTG_DIEPCTL_STALL | \
-      USB_OTG_DIEPCTL_EPDIS);
-    while((in_ep[epnum].DIEPINT & USB_OTG_DIEPINT_EPDISD_Msk) == 0);
-    in_ep[epnum].DIEPINT = USB_OTG_DIEPINT_EPDISD;
+      // Disable the endpoint. Note that both SNAK and STALL are set here.
+      in_ep[epnum].DIEPCTL |= (USB_OTG_DIEPCTL_SNAK | USB_OTG_DIEPCTL_STALL | \
+          USB_OTG_DIEPCTL_EPDIS);
+      while((in_ep[epnum].DIEPINT & USB_OTG_DIEPINT_EPDISD_Msk) == 0);
+      in_ep[epnum].DIEPINT = USB_OTG_DIEPINT_EPDISD;
+    }
 
     // Flush the FIFO, and wait until we have confirmed it cleared.
     USB_OTG_FS->GRSTCTL |= ((epnum - 1) << USB_OTG_GRSTCTL_TXFNUM_Pos);
     USB_OTG_FS->GRSTCTL |= USB_OTG_GRSTCTL_TXFFLSH;
     while((USB_OTG_FS->GRSTCTL & USB_OTG_GRSTCTL_TXFFLSH_Msk) != 0);
   } else {
-    // Asserting GONAK is required to STALL an OUT endpoint.
-    // Simpler to use polling here, we don't use the "B"OUTNAKEFF interrupt
-    // anyway, and it can't be cleared by user code. If this while loop never
-    // finishes, we have bigger problems than just the stack.
-    dev->DCTL |= USB_OTG_DCTL_SGONAK;
-    while((USB_OTG_FS->GINTSTS & USB_OTG_GINTSTS_BOUTNAKEFF_Msk) == 0);
+    // Only disable currently enabled non-control endpoint
+    if ( (epnum == 0) || !(out_ep[epnum].DOEPCTL & USB_OTG_DOEPCTL_EPENA) ){
+      out_ep[epnum].DOEPCTL |= USB_OTG_DIEPCTL_STALL;
+    }else {
+      // Asserting GONAK is required to STALL an OUT endpoint.
+      // Simpler to use polling here, we don't use the "B"OUTNAKEFF interrupt
+      // anyway, and it can't be cleared by user code. If this while loop never
+      // finishes, we have bigger problems than just the stack.
+      dev->DCTL |= USB_OTG_DCTL_SGONAK;
+      while((USB_OTG_FS->GINTSTS & USB_OTG_GINTSTS_BOUTNAKEFF_Msk) == 0);
 
-    // Ditto here- disable the endpoint. Note that only STALL and not SNAK
-    // is set here.
-    out_ep[epnum].DOEPCTL |= (USB_OTG_DOEPCTL_STALL | USB_OTG_DOEPCTL_EPDIS);
-    while((out_ep[epnum].DOEPINT & USB_OTG_DOEPINT_EPDISD_Msk) == 0);
-    out_ep[epnum].DOEPINT = USB_OTG_DOEPINT_EPDISD;
+      // Ditto here- disable the endpoint. Note that only STALL and not SNAK
+      // is set here.
+      out_ep[epnum].DOEPCTL |= (USB_OTG_DOEPCTL_STALL | USB_OTG_DOEPCTL_EPDIS);
+      while((out_ep[epnum].DOEPINT & USB_OTG_DOEPINT_EPDISD_Msk) == 0);
+      out_ep[epnum].DOEPINT = USB_OTG_DOEPINT_EPDISD;
 
-    // Allow other OUT endpoints to keep receiving.
-    dev->DCTL |= USB_OTG_DCTL_CGONAK;
+      // Allow other OUT endpoints to keep receiving.
+      dev->DCTL |= USB_OTG_DCTL_CGONAK;
+    }
   }
 }
 
diff --git a/src/portable/st/stm32f4/hal_stm32f4.c b/src/portable/st/stm32f4/hal_stm32f4.c
deleted file mode 100644
index 68d17b591..000000000
--- a/src/portable/st/stm32f4/hal_stm32f4.c
+++ /dev/null
@@ -1,69 +0,0 @@
-/**************************************************************************/
-/*!
-    @file     hal_nrf5x.c
-    @author   hathach
-
-    @section LICENSE
-
-    Software License Agreement (BSD License)
-
-    Copyright (c) 2018, hathach (tinyusb.org)
-    All rights reserved.
-
-    Redistribution and use in source and binary forms, with or without
-    modification, are permitted provided that the following conditions are met:
-    1. Redistributions of source code must retain the above copyright
-    notice, this list of conditions and the following disclaimer.
-    2. Redistributions in binary form must reproduce the above copyright
-    notice, this list of conditions and the following disclaimer in the
-    documentation and/or other materials provided with the distribution.
-    3. Neither the name of the copyright holders nor the
-    names of its contributors may be used to endorse or promote products
-    derived from this software without specific prior written permission.
-
-    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
-    EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
-    DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-    (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-    ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-    This file is part of the tinyusb stack.
-*/
-/**************************************************************************/
-
-#include "tusb_option.h"
-
-#if TUSB_OPT_DEVICE_ENABLED && CFG_TUSB_MCU == OPT_MCU_STM32F4
-
-#include "stm32f4xx.h"
-
-#include "tusb_hal.h"
-
-/*------------------------------------------------------------------*/
-/* TUSB HAL
- *------------------------------------------------------------------*/
-bool tusb_hal_init(void)
-{
-
-  tusb_hal_int_enable(0);
-  return true;
-}
-
-void tusb_hal_int_enable(uint8_t rhport)
-{
-  (void) rhport;
-  NVIC_EnableIRQ(OTG_FS_IRQn);
-}
-
-void tusb_hal_int_disable(uint8_t rhport)
-{
-  (void) rhport;
-  NVIC_DisableIRQ(OTG_FS_IRQn);
-}
-
-#endif