refactor(audio): separate stream configuration and start

Make configuration a synchronous local operation that selects and opens the endpoint. Start now activates the alternate setting and sets the sampling frequency afterward, including every restart, so devices cannot reset the selected rate with SET_INTERFACE.

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

1 files changed, 9 insertions, 15 deletions

diff --git a/src/class/audio/audio_host.h b/src/class/audio/audio_host.h
index 9fcbe2577..b1e2a9169 100644
--- a/src/class/audio/audio_host.h
+++ b/src/class/audio/audio_host.h
@@ -85,10 +85,6 @@ typedef struct {
   uint8_t               channels;
 } tuh_audio_stream_config_t;
 
-// Asynchronous completion callback of tuh_audio_configure().
-typedef void (*tuh_audio_configure_cb_t)(uint8_t dev_idx, uint8_t stream_idx, tusb_xfer_result_t result,
-                                         uintptr_t user_data);
-
 //--------------------------------------------------------------------+
 // Stream Enumeration
 //--------------------------------------------------------------------+
@@ -118,26 +114,24 @@ uint8_t tuh_audio_active_config(uint8_t dev_idx, uint8_t stream_idx);
 bool tuh_audio_config_get(uint8_t dev_idx, uint8_t stream_idx, uint8_t config_idx, tuh_audio_stream_config_t *config);
 
 //--------------------------------------------------------------------+
-// Configuration (ALSA hw_params analogue, asynchronous)
+// Configuration (ALSA hw_params analogue)
 //--------------------------------------------------------------------+
 
-// Configure the stream with the discrete configuration identified by
-// config_idx. The driver asynchronously:
+// Synchronously configure the stream with the discrete configuration identified by
+// config_idx. The driver:
 //   1. resolves the AS interface and alternate setting,
-//   2. issues SET_INTERFACE (checking submission and transfer result),
-//   3. opens / reconfigures only the selected endpoint,
-//   4. sets the endpoint sampling frequency when supported,
-//   5. initializes the FIFO and packet scheduler.
-// complete_cb is invoked with the final XFER_RESULT_* status.
-bool tuh_audio_configure(uint8_t dev_idx, uint8_t stream_idx, uint8_t config_idx, tuh_audio_configure_cb_t complete_cb,
-                         uintptr_t user_data);
+//   2. initializes the FIFO and packet scheduler,
+//   3. opens / reconfigures only the selected endpoint.
+bool tuh_audio_configure(uint8_t dev_idx, uint8_t stream_idx, uint8_t config_idx);
 
 //--------------------------------------------------------------------+
 // Stream Control / Frame-based Data
 //--------------------------------------------------------------------+
 
-// Start/stop transferring data on a configured stream.
+// Start transferring data by activating the alternate setting selected by
+// configure, then set the endpoint sampling frequency when supported.
 bool tuh_audio_start(uint8_t dev_idx, uint8_t stream_idx);
+// Stop transferring and deactivate the Audio Streaming interface (alt 0).
 bool tuh_audio_stop(uint8_t dev_idx, uint8_t stream_idx);
 
 // Frame-based transfer. One frame = channels * bytes per sample.