diff options
| -rw-r--r-- | sound/usb/midi.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/sound/usb/midi.c b/sound/usb/midi.c index 966051f530bd..9123fc518f07 100644 --- a/sound/usb/midi.c +++ b/sound/usb/midi.c @@ -174,6 +174,8 @@ struct snd_usb_midi_in_endpoint { u8 running_status_length; } ports[0x10]; u8 seen_f5; + bool in_sysex; + u8 last_cin; u8 error_resubmit; int current_port; }; @@ -465,6 +467,39 @@ static void snd_usbmidi_maudio_broken_running_status_input( } /* + * QinHeng CH345 is buggy: every second packet inside a SysEx has not CIN 4 + * but the previously seen CIN, but still with three data bytes. + */ +static void ch345_broken_sysex_input(struct snd_usb_midi_in_endpoint *ep, + uint8_t *buffer, int buffer_length) +{ + unsigned int i, cin, length; + + for (i = 0; i + 3 < buffer_length; i += 4) { + if (buffer[i] == 0 && i > 0) + break; + cin = buffer[i] & 0x0f; + if (ep->in_sysex && + cin == ep->last_cin && + (buffer[i + 1 + (cin == 0x6)] & 0x80) == 0) + cin = 0x4; +#if 0 + if (buffer[i + 1] == 0x90) { + /* + * Either a corrupted running status or a real note-on + * message; impossible to detect reliably. + */ + } +#endif + length = snd_usbmidi_cin_length[cin]; + snd_usbmidi_input_data(ep, 0, &buffer[i + 1], length); + ep->in_sysex = cin == 0x4; + if (!ep->in_sysex) + ep->last_cin = cin; + } +} + +/* * CME protocol: like the standard protocol, but SysEx commands are sent as a * single USB packet preceded by a 0x0F byte. */ @@ -650,6 +685,12 @@ static struct usb_protocol_ops snd_usbmidi_cme_ops = { .output_packet = snd_usbmidi_output_standard_packet, }; +static struct usb_protocol_ops snd_usbmidi_ch345_broken_sysex_ops = { + .input = ch345_broken_sysex_input, + .output = snd_usbmidi_standard_output, + .output_packet = snd_usbmidi_output_standard_packet, +}; + /* * AKAI MPD16 protocol: * @@ -2292,6 +2333,7 @@ int snd_usbmidi_create(struct snd_card *card, err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints); break; case QUIRK_MIDI_CH345: + umidi->usb_protocol_ops = &snd_usbmidi_ch345_broken_sysex_ops; err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints); break; default: |