USB_ReadPMA moved under PCD_FreeUserBuffer. It's valid move.

An interrupt is triggered when the USB hardware has processed one buffer
and waits for the resolution of the firmware to process the next.
That is, USB will process the second buffer or will not process
anything at all. It does not pretend to the current buffer.

Author: makarenya

Diff for: system/Drivers/STM32F1xx_HAL_Driver/Src/stm32f1xx_hal_pcd.c

@@ -1190,6 +1190,7 @@ static HAL_StatusTypeDef PCD_EP_ISR_Handler(PCD_HandleTypeDef *hpcd)
 {
   PCD_EPTypeDef *ep = NULL;
   uint16_t count = 0;
+  uint16_t pmaBuffer = 0;
   uint8_t epindex = 0;
   __IO uint16_t wIstr = 0;  
   __IO uint16_t wEPVal = 0;
@@ -1284,34 +1285,29 @@ static HAL_StatusTypeDef PCD_EP_ISR_Handler(PCD_HandleTypeDef *hpcd)
         /* OUT double Buffering*/
         if (ep->doublebuffer == 0U)
         {
-          count = PCD_GET_EP_RX_CNT(hpcd->Instance, ep->num);
-          if (count != 0U)
-          {
-            USB_ReadPMA(hpcd->Instance, ep->xfer_buff, ep->pmaadress, count);
-          }
+          count = (uint16_t) PCD_GET_EP_RX_CNT(hpcd->Instance, ep->num);
+          pmaBuffer = ep->pmaadress;
         }
         else
         {
-          if (PCD_GET_ENDPOINT(hpcd->Instance, ep->num) & USB_EP_DTOG_RX)
+          if (wEPVal & USB_EP_DTOG_RX)
           {
             /*read from endpoint BUF0Addr buffer*/
-            count = PCD_GET_EP_DBUF0_CNT(hpcd->Instance, ep->num);
-            if (count != 0U)
-            {
-              USB_ReadPMA(hpcd->Instance, ep->xfer_buff, ep->pmaaddr0, count);
-            }
+            count = (uint16_t) PCD_GET_EP_DBUF0_CNT(hpcd->Instance, ep->num);
+            pmaBuffer = ep->pmaaddr0;
           }
           else
           {
             /*read from endpoint BUF1Addr buffer*/
-            count = PCD_GET_EP_DBUF1_CNT(hpcd->Instance, ep->num);
-            if (count != 0U)
-            {
-              USB_ReadPMA(hpcd->Instance, ep->xfer_buff, ep->pmaaddr1, count);
-            }
+            count = (uint16_t) PCD_GET_EP_DBUF1_CNT(hpcd->Instance, ep->num);
+            pmaBuffer = ep->pmaaddr1;
           }
           PCD_FreeUserBuffer(hpcd->Instance, ep->num, PCD_EP_DBUF_OUT);  
         }
+        if (count != 0U)
+        {
+          USB_ReadPMA(hpcd->Instance, ep->xfer_buff, pmaBuffer, count);
+        }
         /*multi-packet on the NON control OUT endpoint*/
         ep->xfer_count+=count;
         ep->xfer_buff+=count;