demo/cdc_loop.c

@@ -32,7 +32,7 @@
 #define HID_RIN_EP      0x83
 #define HID_RIN_SZ      0x10
 
-//#define CDC_LOOPBACK
+#define CDC_LOOPBACK
 #define ENABLE_HID_COMBO
 
 //#define SIGNAL_MODEM  /* uncomment to signal modem capabilities */

src/usbd_stm32f105_otgfs.c

@@ -338,6 +338,7 @@ static int32_t ep_read(uint8_t ep, void* buf, uint16_t blen) {
             tmp >>= 8;
         }
     }
+    _BST(EPOUT(ep)->DOEPCTL, USB_OTG_DOEPCTL_CNAK | USB_OTG_DOEPCTL_EPENA);
     return (len < blen) ? len : blen;
 }
 
@@ -413,9 +414,6 @@ static void evt_poll(usbd_device *dev, usbd_evt_callback callback) {
                 }
                 evt = usbd_evt_epsetup;
                 break;
-            case 0x03:  /* OUT completed */
-            case 0x04:  /* SETUP completed */
-                _BST(EPOUT(ep)->DOEPCTL, USB_OTG_DOEPCTL_CNAK | USB_OTG_DOEPCTL_EPENA);
                 // fall through
             default:
                 /* pop GRXSTSP */

src/usbd_stm32f429_otgfs.c

@@ -350,9 +350,8 @@ static int32_t ep_write(uint8_t ep, const void *buf, uint16_t blen) {
     len = (blen + 3) >> 2;
     /* no enough space in TX fifo */
     if (len > 0 && len > _FLD2VAL(USB_OTG_DTXFSTS_INEPTFSAV, epi->DTXFSTS)) return -1;
-    //epi->DIEPTSIZ = 0;
     epi->DIEPTSIZ = (1 << 19) + blen;
-    _BST(epi->DIEPCTL, USB_OTG_DIEPCTL_EPENA | USB_OTG_DIEPCTL_CNAK);
+    _BMD(epi->DIEPCTL, USB_OTG_DIEPCTL_STALL, USB_OTG_DOEPCTL_EPENA | USB_OTG_DOEPCTL_CNAK);
     /* push data to FIFO */
     for (int idx = 0; idx < blen; idx++) {
         tmp |= (uint32_t)((const uint8_t*)buf)[idx] << ((idx & 0x03) << 3);