fix(audio): drive streams from transfer completion

Keep capture and playback transfers continuously armed from their completion callbacks. Capture overwrites the oldest complete frames when full, while playback sends silence on underrun without consuming partial queued audio.

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

1 files changed, 3 insertions, 3 deletions

diff --git a/examples/host/audio_host/README.md b/examples/host/audio_host/README.md
index 88c948ccd..bbb3a7684 100644
--- a/examples/host/audio_host/README.md
+++ b/examples/host/audio_host/README.md
@@ -98,10 +98,10 @@ Edit `src/tusb_config.h` to modify:
 - `CFG_TUH_AUDIO_MAX`: Maximum number of audio devices supported
 - `CFG_TUH_AUDIO_EPIN_BUFSIZE`: Maximum size of one capture transfer the driver submits (configurations needing a larger per-poll-interval packet are rejected)
 - `CFG_TUH_AUDIO_EPOUT_BUFSIZE`: Maximum size of one playback transfer the driver submits
-- `CFG_TUH_AUDIO_STREAM_BUFSIZE`: Per-stream FIFO depth in bytes (default 1024, i.e. four 256 B packets)
+- `CFG_TUH_AUDIO_STREAM_BUFSIZE`: Per-stream FIFO depth in bytes (default 1024, i.e. four 256 B packets); capture overwrites the oldest frames when full
 
 ## 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.
-- `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.
-- Isochronous transfers require the host to poll `tuh_task()` continuously; the capture FIFO absorbs short scheduling gaps, but frames are dropped when it overflows.
+- `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.