1 files changed, 27 insertions, 8 deletions

diff --git a/src/tusb.c b/src/tusb.c
index 3852da76b..c589e105e 100644
--- a/src/tusb.c
+++ b/src/tusb.c
@@ -387,8 +387,12 @@ TU_ATTR_ALWAYS_INLINE static inline bool stream_xfer(uint8_t hwid, tu_edpt_strea
     #endif
   } else {
     #if CFG_TUD_ENABLED
-    return usbd_edpt_xfer(hwid, s->ep_addr, count ? s->ep_buf : NULL, count, false);
-    #endif
+    if (s->ep_buf == NULL) {
+      return usbd_edpt_xfer_fifo(hwid, s->ep_addr, &s->ff, count, false);
+    } else {
+      return usbd_edpt_xfer(hwid, s->ep_addr, count ? s->ep_buf : NULL, count, false);
+    }
+  #endif
   }
   return false;
 }
@@ -419,12 +423,17 @@ bool tu_edpt_stream_write_zlp_if_needed(uint8_t hwid, tu_edpt_stream_t* s, uint3
 }
 
 uint32_t tu_edpt_stream_write_xfer(uint8_t hwid, tu_edpt_stream_t* s) {
-  // skip if no data
-  TU_VERIFY(tu_fifo_count(&s->ff) > 0, 0);
+  const uint16_t ff_count = tu_fifo_count(&s->ff);
+  TU_VERIFY(ff_count > 0, 0); // skip if no data
   TU_VERIFY(stream_claim(hwid, s), 0);
 
   // Pull data from FIFO -> EP buf
-  const uint16_t count = tu_fifo_read_n(&s->ff, s->ep_buf, s->ep_bufsize);
+  uint16_t count;
+  if (s->ep_buf == NULL) {
+    count = ff_count;
+  } else {
+    count = tu_fifo_read_n(&s->ff, s->ep_buf, s->ep_bufsize);
+  }
 
   if (count > 0) {
     TU_ASSERT(stream_xfer(hwid, s, count), 0);
@@ -441,7 +450,8 @@ uint32_t tu_edpt_stream_write(uint8_t hwid, tu_edpt_stream_t *s, const void *buf
   TU_VERIFY(bufsize > 0); // TODO support ZLP
 
   if (0 == tu_fifo_depth(&s->ff)) {
-    // no fifo for buffered
+    // non-fifo mode, ep_buf must be valid
+    TU_VERIFY(s->ep_buf != NULL, 0);
     TU_VERIFY(stream_claim(hwid, s), 0);
     const uint32_t xact_len = tu_min32(bufsize, s->ep_bufsize);
     memcpy(s->ep_buf, buffer, xact_len);
@@ -464,6 +474,7 @@ uint32_t tu_edpt_stream_write_available(uint8_t hwid, tu_edpt_stream_t* s) {
   if (tu_fifo_depth(&s->ff) > 0) {
     return (uint32_t) tu_fifo_remaining(&s->ff);
   } else {
+    // non-fifo mode
     bool is_busy = true;
     if (s->is_host) {
       #if CFG_TUH_ENABLED
@@ -483,7 +494,7 @@ uint32_t tu_edpt_stream_write_available(uint8_t hwid, tu_edpt_stream_t* s) {
 //--------------------------------------------------------------------+
 uint32_t tu_edpt_stream_read_xfer(uint8_t hwid, tu_edpt_stream_t* s) {
   if (0 == tu_fifo_depth(&s->ff)) {
-    // no fifo for buffered
+    // non-fifo mode
     TU_VERIFY(stream_claim(hwid, s), 0);
     TU_ASSERT(stream_xfer(hwid, s, s->ep_bufsize), 0);
     return s->ep_bufsize;
@@ -517,7 +528,15 @@ uint32_t tu_edpt_stream_read_xfer(uint8_t hwid, tu_edpt_stream_t* s) {
 }
 
 uint32_t tu_edpt_stream_read(uint8_t hwid, tu_edpt_stream_t* s, void* buffer, uint32_t bufsize) {
-  const uint32_t num_read = tu_fifo_read_n(&s->ff, buffer, (uint16_t)bufsize);
+  uint32_t num_read;
+  if (tu_fifo_depth(&s->ff) > 0) {
+    num_read = tu_fifo_read_n(&s->ff, buffer, (uint16_t)bufsize);
+  } else {
+    // non-fifo mode
+    memcpy(buffer, s->ep_buf, bufsize);
+    num_read = bufsize;
+  }
+
   tu_edpt_stream_read_xfer(hwid, s);
   return num_read;
 }