diff --git a/targets/TARGET_STM/TARGET_STM32F1/device/stm32f1xx_hal_pcd.c b/targets/TARGET_STM/TARGET_STM32F1/device/stm32f1xx_hal_pcd.c
index 8e0ddbe30b..11c636a8b9 100644
--- a/targets/TARGET_STM/TARGET_STM32F1/device/stm32f1xx_hal_pcd.c
+++ b/targets/TARGET_STM/TARGET_STM32F1/device/stm32f1xx_hal_pcd.c
@@ -1152,7 +1152,7 @@ static HAL_StatusTypeDef PCD_WriteEmptyTxFifo(PCD_HandleTypeDef *hpcd, uint32_t
 {
   USB_OTG_GlobalTypeDef *USBx = hpcd->Instance;  
   USB_OTG_EPTypeDef *ep = NULL;
-  int32_t len = 0;
+  uint32_t len;
   uint32_t len32b = 0U;
   uint32_t fifoemptymsk = 0U;
   
@@ -1185,7 +1185,7 @@ static HAL_StatusTypeDef PCD_WriteEmptyTxFifo(PCD_HandleTypeDef *hpcd, uint32_t
     ep->xfer_count += len;
   }
   
-  if(len <= 0)
+  if (ep->xfer_count >= ep->xfer_len)
   {
     fifoemptymsk = 0x01U << epnum;
     USBx_DEVICE->DIEPEMPMSK &= ~fifoemptymsk;
diff --git a/targets/TARGET_STM/TARGET_STM32F2/device/stm32f2xx_hal_pcd.c b/targets/TARGET_STM/TARGET_STM32F2/device/stm32f2xx_hal_pcd.c
index 218c10a362..ee1703bbd1 100644
--- a/targets/TARGET_STM/TARGET_STM32F2/device/stm32f2xx_hal_pcd.c
+++ b/targets/TARGET_STM/TARGET_STM32F2/device/stm32f2xx_hal_pcd.c
@@ -1213,7 +1213,7 @@ static HAL_StatusTypeDef PCD_WriteEmptyTxFifo(PCD_HandleTypeDef *hpcd, uint32_t
 {
   USB_OTG_GlobalTypeDef *USBx = hpcd->Instance;  
   USB_OTG_EPTypeDef *ep;
-  int32_t len = 0U;
+  uint32_t len;
   uint32_t len32b;
   uint32_t fifoemptymsk = 0U;
 
@@ -1247,7 +1247,7 @@ static HAL_StatusTypeDef PCD_WriteEmptyTxFifo(PCD_HandleTypeDef *hpcd, uint32_t
     ep->xfer_count += len;
   }
   
-  if(len <= 0U)
+  if (ep->xfer_count >= ep->xfer_len)
   {
     fifoemptymsk = 0x1U << epnum;
     atomic_clr_u32(&USBx_DEVICE->DIEPEMPMSK,  fifoemptymsk);
diff --git a/targets/TARGET_STM/TARGET_STM32F4/device/stm32f4xx_hal_pcd.c b/targets/TARGET_STM/TARGET_STM32F4/device/stm32f4xx_hal_pcd.c
index 44e191553c..a6ed3193fe 100644
--- a/targets/TARGET_STM/TARGET_STM32F4/device/stm32f4xx_hal_pcd.c
+++ b/targets/TARGET_STM/TARGET_STM32F4/device/stm32f4xx_hal_pcd.c
@@ -1311,7 +1311,7 @@ static HAL_StatusTypeDef PCD_WriteEmptyTxFifo(PCD_HandleTypeDef *hpcd, uint32_t
 {
   USB_OTG_GlobalTypeDef *USBx = hpcd->Instance;  
   USB_OTG_EPTypeDef *ep;
-  int32_t len = 0U;
+  uint32_t len;
   uint32_t len32b;
   uint32_t fifoemptymsk = 0U;
 
@@ -1345,7 +1345,7 @@ static HAL_StatusTypeDef PCD_WriteEmptyTxFifo(PCD_HandleTypeDef *hpcd, uint32_t
     ep->xfer_count += len;
   }
   
-  if(len <= 0U)
+  if (ep->xfer_count >= ep->xfer_len)
   {
     fifoemptymsk = 0x1U << epnum;
 /* MBED */
diff --git a/targets/TARGET_STM/TARGET_STM32F7/device/stm32f7xx_hal_pcd.c b/targets/TARGET_STM/TARGET_STM32F7/device/stm32f7xx_hal_pcd.c
index 66599a979c..2785ae76bd 100644
--- a/targets/TARGET_STM/TARGET_STM32F7/device/stm32f7xx_hal_pcd.c
+++ b/targets/TARGET_STM/TARGET_STM32F7/device/stm32f7xx_hal_pcd.c
@@ -145,7 +145,7 @@ HAL_StatusTypeDef HAL_PCD_Init(PCD_HandleTypeDef *hpcd)
 
   // MBED: added
   if(hpcd->State == HAL_PCD_STATE_RESET)
-  {  
+  {
     /* Allocate lock resource and initialize it */
     hpcd->Lock = HAL_UNLOCKED;
 	for (i = 0; i < hpcd->Init.dev_endpoints ; i++)
@@ -1300,7 +1300,7 @@ static HAL_StatusTypeDef PCD_WriteEmptyTxFifo(PCD_HandleTypeDef *hpcd, uint32_t
 {
   USB_OTG_GlobalTypeDef *USBx = hpcd->Instance;
   USB_OTG_EPTypeDef *ep;
-  int32_t len = 0;
+  uint32_t len;
   uint32_t len32b;
   uint32_t fifoemptymsk = 0;
 
@@ -1334,7 +1334,7 @@ static HAL_StatusTypeDef PCD_WriteEmptyTxFifo(PCD_HandleTypeDef *hpcd, uint32_t
     ep->xfer_count += len;
   }
 
-  if(len <= 0)
+  if (ep->xfer_count >= ep->xfer_len)
   {
     fifoemptymsk = 0x1 << epnum;
     atomic_clr_u32(&USBx_DEVICE->DIEPEMPMSK,  fifoemptymsk); // MBED: changed
diff --git a/targets/TARGET_STM/TARGET_STM32L4/device/stm32l4xx_hal_pcd.c b/targets/TARGET_STM/TARGET_STM32L4/device/stm32l4xx_hal_pcd.c
index 453922e740..5879b40698 100644
--- a/targets/TARGET_STM/TARGET_STM32L4/device/stm32l4xx_hal_pcd.c
+++ b/targets/TARGET_STM/TARGET_STM32L4/device/stm32l4xx_hal_pcd.c
@@ -1428,7 +1428,7 @@ static HAL_StatusTypeDef PCD_WriteEmptyTxFifo(PCD_HandleTypeDef *hpcd, uint32_t
 {
   USB_OTG_GlobalTypeDef *USBx = hpcd->Instance;  
   USB_OTG_EPTypeDef *ep = NULL;
-  int32_t len = 0U;
+  uint32_t len;
   uint32_t len32b = 0;
   uint32_t fifoemptymsk = 0;
 
@@ -1462,7 +1462,7 @@ static HAL_StatusTypeDef PCD_WriteEmptyTxFifo(PCD_HandleTypeDef *hpcd, uint32_t
     ep->xfer_count += len;
   }
   
-  if(len <= 0)
+  if (ep->xfer_count >= ep->xfer_len)
   {
     fifoemptymsk = 0x1 << epnum;
     // Added for MBED PR #3062