From 8508fa2e7472f673edbeedf1b1d2b7a6bb898ecc Mon Sep 17 00:00:00 2001 From: Artem Egorkine Date: Sun, 25 Dec 2022 12:57:27 +0200 Subject: ALSA: line6: correct midi status byte when receiving data from podxt A PODxt device sends 0xb2, 0xc2 or 0xf2 as a status byte for MIDI messages over USB that should otherwise have a 0xb0, 0xc0 or 0xf0 status byte. This is usually corrected by the driver on other OSes. This fixes MIDI sysex messages sent by PODxt. [ tiwai: fixed white spaces ] Signed-off-by: Artem Egorkine Cc: Link: https://lore.kernel.org/r/20221225105728.1153989-1-arteme@gmail.com Signed-off-by: Takashi Iwai --- sound/usb/line6/driver.c | 3 ++- sound/usb/line6/midi.c | 3 ++- sound/usb/line6/midibuf.c | 25 +++++++++++++++++-------- sound/usb/line6/midibuf.h | 5 ++++- sound/usb/line6/pod.c | 3 ++- 5 files changed, 27 insertions(+), 12 deletions(-) (limited to 'sound') diff --git a/sound/usb/line6/driver.c b/sound/usb/line6/driver.c index 59faa5a9a714..b67617b68e50 100644 --- a/sound/usb/line6/driver.c +++ b/sound/usb/line6/driver.c @@ -304,7 +304,8 @@ static void line6_data_received(struct urb *urb) for (;;) { done = line6_midibuf_read(mb, line6->buffer_message, - LINE6_MIDI_MESSAGE_MAXLEN); + LINE6_MIDI_MESSAGE_MAXLEN, + LINE6_MIDIBUF_READ_RX); if (done <= 0) break; diff --git a/sound/usb/line6/midi.c b/sound/usb/line6/midi.c index ba0e2b7e8fe1..d52355de2bbc 100644 --- a/sound/usb/line6/midi.c +++ b/sound/usb/line6/midi.c @@ -56,7 +56,8 @@ static void line6_midi_transmit(struct snd_rawmidi_substream *substream) for (;;) { done = line6_midibuf_read(mb, chunk, - LINE6_FALLBACK_MAXPACKETSIZE); + LINE6_FALLBACK_MAXPACKETSIZE, + LINE6_MIDIBUF_READ_TX); if (done == 0) break; diff --git a/sound/usb/line6/midibuf.c b/sound/usb/line6/midibuf.c index 6a70463f82c4..e7f830f7526c 100644 --- a/sound/usb/line6/midibuf.c +++ b/sound/usb/line6/midibuf.c @@ -9,6 +9,7 @@ #include "midibuf.h" + static int midibuf_message_length(unsigned char code) { int message_length; @@ -20,12 +21,7 @@ static int midibuf_message_length(unsigned char code) message_length = length[(code >> 4) - 8]; } else { - /* - Note that according to the MIDI specification 0xf2 is - the "Song Position Pointer", but this is used by Line 6 - to send sysex messages to the host. - */ - static const int length[] = { -1, 2, -1, 2, -1, -1, 1, 1, 1, 1, + static const int length[] = { -1, 2, 2, 2, -1, -1, 1, 1, 1, -1, 1, 1, 1, -1, 1, 1 }; message_length = length[code & 0x0f]; @@ -125,7 +121,7 @@ int line6_midibuf_write(struct midi_buffer *this, unsigned char *data, } int line6_midibuf_read(struct midi_buffer *this, unsigned char *data, - int length) + int length, int read_type) { int bytes_used; int length1, length2; @@ -148,9 +144,22 @@ int line6_midibuf_read(struct midi_buffer *this, unsigned char *data, length1 = this->size - this->pos_read; - /* check MIDI command length */ command = this->buf[this->pos_read]; + /* + PODxt always has status byte lower nibble set to 0010, + when it means to send 0000, so we correct if here so + that control/program changes come on channel 1 and + sysex message status byte is correct + */ + if (read_type == LINE6_MIDIBUF_READ_RX) { + if (command == 0xb2 || command == 0xc2 || command == 0xf2) { + unsigned char fixed = command & 0xf0; + this->buf[this->pos_read] = fixed; + command = fixed; + } + } + /* check MIDI command length */ if (command & 0x80) { midi_length = midibuf_message_length(command); this->command_prev = command; diff --git a/sound/usb/line6/midibuf.h b/sound/usb/line6/midibuf.h index 124a8f9f7e96..542e8d836f87 100644 --- a/sound/usb/line6/midibuf.h +++ b/sound/usb/line6/midibuf.h @@ -8,6 +8,9 @@ #ifndef MIDIBUF_H #define MIDIBUF_H +#define LINE6_MIDIBUF_READ_TX 0 +#define LINE6_MIDIBUF_READ_RX 1 + struct midi_buffer { unsigned char *buf; int size; @@ -23,7 +26,7 @@ extern void line6_midibuf_destroy(struct midi_buffer *mb); extern int line6_midibuf_ignore(struct midi_buffer *mb, int length); extern int line6_midibuf_init(struct midi_buffer *mb, int size, int split); extern int line6_midibuf_read(struct midi_buffer *mb, unsigned char *data, - int length); + int length, int read_type); extern void line6_midibuf_reset(struct midi_buffer *mb); extern int line6_midibuf_write(struct midi_buffer *mb, unsigned char *data, int length); diff --git a/sound/usb/line6/pod.c b/sound/usb/line6/pod.c index cd41aa7f0385..d173971e5f02 100644 --- a/sound/usb/line6/pod.c +++ b/sound/usb/line6/pod.c @@ -159,8 +159,9 @@ static struct line6_pcm_properties pod_pcm_properties = { .bytes_per_channel = 3 /* SNDRV_PCM_FMTBIT_S24_3LE */ }; + static const char pod_version_header[] = { - 0xf2, 0x7e, 0x7f, 0x06, 0x02 + 0xf0, 0x7e, 0x7f, 0x06, 0x02 }; static char *pod_alloc_sysex_buffer(struct usb_line6_pod *pod, int code, -- cgit v1.2.3