address copilot review findings

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

3 files changed, 51 insertions, 4 deletions

diff --git a/examples/host/audio_host/README.md b/examples/host/audio_host/README.md
index 5413895a4..27e6425b8 100644
--- a/examples/host/audio_host/README.md
+++ b/examples/host/audio_host/README.md
@@ -52,8 +52,9 @@ make BOARD=<your_board> all
 ## Flashing
 
 ```bash
-# Using CMake
-ninja flash
+# Using CMake: list the board-specific flash targets, then select one
+ninja -t targets
+ninja audio_host-jlink # example for a board with J-Link support
 
 # Using Make
 make BOARD=<your_board> flash
@@ -111,5 +112,6 @@ Edit `src/tusb_config.h` to modify:
 ## Notes
 
 - While a stream is running, the driver keeps one isochronous transfer in flight and re-submits on completion, so transfers follow the endpoint's `bInterval`. `tuh_audio_capture_cb()` / `tuh_audio_playback_cb()` report each completed transfer; `tuh_audio_err_cb()` reports failures. The example restarts the failed stream automatically 100 ms after the error callback.
+- Capture and playback streams in the same Audio Control instance must use the same sample rate.
 - `tuh_audio_read()` / `tuh_audio_write()` are non-blocking FIFO operations: they return the number of whole frames actually queued/read (0 when the FIFO is empty/full or the stream is not running), and `tuh_audio_read_available()` / `tuh_audio_write_available()` report the FIFO occupancy in frames. `tuh_audio_write()` only queues data; the playback transfer-completion chain sends it, or sends silence when the FIFO does not contain a complete polling interval without consuming the partial data.
 - Isochronous transfers require the host to poll `tuh_task()` continuously; the capture FIFO absorbs short scheduling gaps and overwrites the oldest frames when full.
diff --git a/src/class/audio/audio_host.c b/src/class/audio/audio_host.c
index 2a8df9075..98822b9c0 100644
--- a/src/class/audio/audio_host.c
+++ b/src/class/audio/audio_host.c
@@ -325,6 +325,8 @@ static tuh_audio_stream_t *audioh_find_stream(uint8_t dev_addr, uint8_t ep_addr)
 // Packet scheduler
 //--------------------------------------------------------------------+
 
+static void audioh_stream_error(tuh_audio_stream_t *s, uint16_t xferred_bytes);
+
 // Re-arm the capture endpoint: request one full packet (the device sends at
 // most its max packet size per poll interval). The overwritable FIFO retains
 // the newest capture frames when the application cannot drain it in time.
@@ -335,7 +337,9 @@ static void audioh_stream_capture_xfer(tuh_audio_stream_t *s) {
   TU_VERIFY(usbh_edpt_claim(s->daddr, map->ep_addr), ); // one transfer in flight
 
   // ep_size is guaranteed <= CFG_TUH_AUDIO_EPIN_BUFSIZE by enumeration
-  TU_ASSERT(usbh_edpt_xfer(s->daddr, map->ep_addr, s->edpt.ep_buf, map->ep_size), );
+  if (!usbh_edpt_xfer(s->daddr, map->ep_addr, s->edpt.ep_buf, map->ep_size)) {
+    audioh_stream_error(s, 0);
+  }
 }
 
 // Submit the next queued playback packet. Fractional frames per endpoint poll
@@ -366,7 +370,10 @@ static void audioh_stream_playback_xfer(tuh_audio_stream_t *s) {
     tu_fifo_read_n(&s->edpt.ff, s->edpt.ep_buf, bytes);
   }
 
-  TU_ASSERT(usbh_edpt_xfer(s->daddr, map->ep_addr, s->edpt.ep_buf, bytes), );
+  if (!usbh_edpt_xfer(s->daddr, map->ep_addr, s->edpt.ep_buf, bytes)) {
+    audioh_stream_error(s, 0);
+    return;
+  }
   s->rem_acc = next_rem_acc;
 }
 
diff --git a/test/unit-test/test/host/audio/test_audio_host.c b/test/unit-test/test/host/audio/test_audio_host.c
index f02c44095..e5056bc2c 100644
--- a/test/unit-test/test/host/audio/test_audio_host.c
+++ b/test/unit-test/test/host/audio/test_audio_host.c
@@ -123,6 +123,9 @@ bool usbh_edpt_xfer_with_callback(uint8_t dev_addr, uint8_t ep_addr, uint8_t *bu
     memcpy(edpt_xfer_data[edpt_xfer_count], buffer, TU_MIN(sizeof(edpt_xfer_data[0]), total_bytes));
     edpt_xfer_count++;
   }
+  if (!edpt_xfer_result) {
+    edpt_busy = false; // match usbh_edpt_xfer() cleanup after HCD rejection
+  }
   return edpt_xfer_result;
 }
 
@@ -749,6 +752,41 @@ void test_audio_host_reports_asynchronous_start_failures(void) {
   TEST_ASSERT_EQUAL_UINT8(3, err_cb_count);
 }
 
+void test_audio_host_reports_capture_submission_failure(void) {
+  mount_descriptors(capture_fu_before_usb_output, sizeof(capture_fu_before_usb_output));
+  TEST_ASSERT_TRUE(tuh_audio_configure(0, 0, 0));
+
+  edpt_xfer_result = false;
+  TEST_ASSERT_TRUE(tuh_audio_start(0, 0));
+  complete_interface_set(XFER_RESULT_SUCCESS);
+  complete_control_xfer(XFER_RESULT_SUCCESS);
+
+  TEST_ASSERT_EQUAL_UINT8(1, err_cb_count);
+  TEST_ASSERT_EQUAL_UINT8(0, err_cb_idx);
+  TEST_ASSERT_EQUAL_UINT8(0, err_cb_stream_idx);
+  TEST_ASSERT_EQUAL_UINT16(0, err_cb_xferred_bytes);
+
+  edpt_xfer_result = true;
+  TEST_ASSERT_TRUE(tuh_audio_start(0, 0));
+}
+
+void test_audio_host_reports_playback_submission_failure(void) {
+  mount_descriptors(playback_44100_max_packets_only, sizeof(playback_44100_max_packets_only));
+  TEST_ASSERT_TRUE(tuh_audio_configure(0, 0, 0));
+
+  edpt_xfer_result = false;
+  TEST_ASSERT_TRUE(tuh_audio_start(0, 0));
+  complete_interface_set(XFER_RESULT_SUCCESS);
+
+  TEST_ASSERT_EQUAL_UINT8(1, err_cb_count);
+  TEST_ASSERT_EQUAL_UINT8(0, err_cb_idx);
+  TEST_ASSERT_EQUAL_UINT8(0, err_cb_stream_idx);
+  TEST_ASSERT_EQUAL_UINT16(0, err_cb_xferred_bytes);
+
+  edpt_xfer_result = true;
+  TEST_ASSERT_TRUE(tuh_audio_start(0, 0));
+}
+
 void test_audio_host_keeps_running_when_stop_cannot_be_submitted(void) {
   mount_descriptors(capture_fu_before_usb_output, sizeof(capture_fu_before_usb_output));
   TEST_ASSERT_TRUE(tuh_audio_configure(0, 0, 0));