dcd/ch32fs: set EP to NAK earlier to reduce spuroius transfer

Signed-off-by: HiFiPhile <[email protected]>

1 files changed, 17 insertions, 5 deletions

diff --git a/src/portable/wch/dcd_ch32_usbfs.c b/src/portable/wch/dcd_ch32_usbfs.c
index 8f583510c..3ba6eee87 100644
--- a/src/portable/wch/dcd_ch32_usbfs.c
+++ b/src/portable/wch/dcd_ch32_usbfs.c
@@ -66,6 +66,13 @@ static struct {
 static void update_in(uint8_t rhport, uint8_t ep, bool force) {
   struct usb_xfer* xfer = &data.xfer[ep][TUSB_DIR_IN];
   if (xfer->valid) {
+    // Set EP to NAK to avoid spurious tramsfer
+    if (ep == 0) {
+      EP_TX_CTRL(0) = USBFS_EP_T_RES_NAK | (data.ep0_tog ? USBFS_EP_T_TOG : 0);
+    } else if (!data.isochronous[ep]) {
+      EP_TX_CTRL(ep) = (EP_TX_CTRL(ep) & ~(USBFS_EP_T_RES_MASK)) | USBFS_EP_T_RES_NAK;
+    }
+
     if (force || xfer->len) {
       size_t len = TU_MIN(xfer->max_size, xfer->len);
       if (ep == 0) {
@@ -101,6 +108,13 @@ static void update_in(uint8_t rhport, uint8_t ep, bool force) {
 static void update_out(uint8_t rhport, uint8_t ep, size_t rx_len) {
   struct usb_xfer* xfer = &data.xfer[ep][TUSB_DIR_OUT];
   if (xfer->valid) {
+    // Set EP to NAK to avoid spurious tramsfer
+    if (ep == 0) {
+      EP_RX_CTRL(0) = USBFS_EP_R_RES_NAK;
+    } else if (!data.isochronous[ep]) {
+      EP_RX_CTRL(ep) = (EP_RX_CTRL(ep) & ~USBFS_EP_R_RES_MASK) | USBFS_EP_R_RES_NAK;
+    }
+
     size_t len = TU_MIN(xfer->max_size, TU_MIN(xfer->len, rx_len));
     if (ep == 3) {
       memcpy(xfer->buffer, data.ep3_buffer.out, len);
@@ -116,9 +130,7 @@ static void update_out(uint8_t rhport, uint8_t ep, size_t rx_len) {
       dcd_event_xfer_complete(rhport, ep, xfer->processed_len, XFER_RESULT_SUCCESS, true);
     }
 
-    if (ep == 0) {
-      EP_RX_CTRL(0) = USBFS_EP_R_RES_ACK;
-    } else {
+    if (ep != 0) {
       uint8_t rx_res = data.isochronous[ep]
                       ? USBFS_EP_R_RES_NYET
                       : (xfer->valid ? USBFS_EP_R_RES_ACK : USBFS_EP_R_RES_NAK);
@@ -173,10 +185,11 @@ void dcd_int_handler(uint8_t rhport) {
   if (status & USBFS_INT_FG_TRANSFER) {
     uint8_t ep = USBFS_INT_ST_MASK_UIS_ENDP(USBOTG_FS->INT_ST);
     uint8_t token = USBFS_INT_ST_MASK_UIS_TOKEN(USBOTG_FS->INT_ST);
+    uint16_t rx_len = USBOTG_FS->RX_LEN;
+    USBOTG_FS->INT_FG = USBFS_INT_FG_TRANSFER;
 
     switch (token) {
       case PID_OUT: {
-        uint16_t rx_len = USBOTG_FS->RX_LEN;
         update_out(rhport, ep, rx_len);
         break;
       }
@@ -198,7 +211,6 @@ void dcd_int_handler(uint8_t rhport) {
         break;
     }
 
-    USBOTG_FS->INT_FG = USBFS_INT_FG_TRANSFER;
   } else if (status & USBFS_INT_FG_BUS_RST) {
     data.ep0_tog = true;
     data.xfer[0][TUSB_DIR_OUT].max_size = 64;