diff options
| -rw-r--r-- | src/class/midi/midi_host.h | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/src/class/midi/midi_host.h b/src/class/midi/midi_host.h index b9ab0130d..4eefed4ba 100644 --- a/src/class/midi/midi_host.h +++ b/src/class/midi/midi_host.h @@ -38,11 +38,16 @@ extern "C" { // Class Driver Configuration //--------------------------------------------------------------------+ #ifndef CFG_TUH_MIDI_RX_BUFSIZE - #define CFG_TUH_MIDI_RX_BUFSIZE TUH_EPSIZE_BULK_MAX + // Default sized to 2x the bulk endpoint to absorb residue left in the FIFO + // when tuh_midi_stream_read() stops early on a cable-number transition. + // Sizing this equal to the endpoint packet size (the historical default) + // can cause the next bulk IN transfer to fail to queue silently, wedging + // the stream. See the drain-loop note on tuh_midi_stream_read() below. + #define CFG_TUH_MIDI_RX_BUFSIZE (2 * TUH_EPSIZE_BULK_MAX) #endif #ifndef CFG_TUH_MIDI_TX_BUFSIZE - #define CFG_TUH_MIDI_TX_BUFSIZE TUH_EPSIZE_BULK_MAX + #define CFG_TUH_MIDI_TX_BUFSIZE (2 * TUH_EPSIZE_BULK_MAX) #endif #ifndef CFG_TUH_MIDI_EP_BUFSIZE @@ -150,6 +155,13 @@ uint32_t tuh_midi_stream_write(uint8_t idx, uint8_t cable_num, const uint8_t *p_ // Note that this function ignores the CIN field of the MIDI packet // because a number of commercial devices out there do not encode // it properly. +// +// NOTE: this function terminates when it encounters an event whose cable +// number differs from the one being returned. Applications should invoke +// it in a loop until it returns 0 (or until tuh_midi_read_available() +// returns 0) to guarantee the stream FIFO is fully drained per callback. +// Leaving bytes in the FIFO across callbacks can prevent subsequent bulk +// IN transfers from landing. uint32_t tuh_midi_stream_read(uint8_t idx, uint8_t *p_cable_num, uint8_t *p_buffer, uint16_t bufsize); #endif |