diff options
Diffstat (limited to 'src/class/midi/midi2_device.c')
| -rw-r--r-- | src/class/midi/midi2_device.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/src/class/midi/midi2_device.c b/src/class/midi/midi2_device.c index f7d338ede..a005c8e51 100644 --- a/src/class/midi/midi2_device.c +++ b/src/class/midi/midi2_device.c @@ -347,11 +347,20 @@ uint32_t tud_midi2_n_ump_write(uint8_t itf, const uint32_t* words, uint32_t coun while (written < count) { uint8_t mt = (uint8_t)((words[written] >> 28) & 0x0F); uint8_t pkt_words = midi2_ump_word_count(mt); + uint32_t pkt_bytes = (uint32_t)pkt_words * 4; if (written + pkt_words > count) break; - if (tu_edpt_stream_write_available(ep_tx) < pkt_words * 4) break; + if (tu_edpt_stream_write_available(ep_tx) < pkt_bytes) break; + + // Flush whole packets already queued before adding one that would cross + // the wMaxPacketSize boundary. Prevents an UMP message from being split + // across two USB transfers, which would corrupt the host RX context. + uint16_t ff_count = tu_fifo_count(&ep_tx->ff); + if (ff_count > 0 && ff_count + pkt_bytes > ep_tx->mps) { + tu_edpt_stream_write_xfer(ep_tx); + } - tu_edpt_stream_write(ep_tx, &words[written], pkt_words * 4); + tu_edpt_stream_write(ep_tx, &words[written], pkt_bytes); written += pkt_words; } |