6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Takashi Iwai <tiwai@xxxxxxx>
commit 952b13c215234855d75ef4b5bb0138075e73677c upstream.
The current conversion from the legacy SysEx event to UMP SysEx packet
in the sequencer core has a couple of issues:
* The first packet trims the SysEx start byte (0xf0), hence it
contains only 5 bytes instead of 6. This isn't wrong, per
specification, but it's strange not to fill 6 bytes.
* When the SysEx end marker (0xf7) is placed at the first byte of the
next packet, it'll end up with an empty data just with the END
status. It can be rather folded into the previous packet with the
END status.
This patch tries to address those issues. The first packet may have 6
bytes even with the SysEx start, and an empty packet with the SysEx
end marker is omitted.
Fixes: e9e02819a98a ("ALSA: seq: Automatic conversion of UMP events")
Cc: <stable@xxxxxxxxxxxxxxx>
Link: https://patch.msgid.link/20240726143455.3254-1-tiwai@xxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
sound/core/seq/seq_ump_convert.c | 41 +++++++++++++++++++-------------
1 file changed, 25 insertions(+), 16 deletions(-)
diff --git a/sound/core/seq/seq_ump_convert.c b/sound/core/seq/seq_ump_convert.c
index e90b27a135e6..d9dacfbe4a9a 100644
--- a/sound/core/seq/seq_ump_convert.c
+++ b/sound/core/seq/seq_ump_convert.c
@@ -1192,44 +1192,53 @@ static int cvt_sysex_to_ump(struct snd_seq_client *dest,
{
struct snd_seq_ump_event ev_cvt;
unsigned char status;
- u8 buf[6], *xbuf;
+ u8 buf[8], *xbuf;
int offset = 0;
int len, err;
+ bool finished = false;
if (!snd_seq_ev_is_variable(event))
return 0;
setup_ump_event(&ev_cvt, event);
- for (;;) {
+ while (!finished) {
len = snd_seq_expand_var_event_at(event, sizeof(buf), buf, offset);
if (len <= 0)
break;
- if (WARN_ON(len > 6))
+ if (WARN_ON(len > sizeof(buf)))
break;
- offset += len;
+
xbuf = buf;
+ status = UMP_SYSEX_STATUS_CONTINUE;
+ /* truncate the sysex start-marker */
if (*xbuf == UMP_MIDI1_MSG_SYSEX_START) {
status = UMP_SYSEX_STATUS_START;
- xbuf++;
len--;
- if (len > 0 && xbuf[len - 1] == UMP_MIDI1_MSG_SYSEX_END) {
- status = UMP_SYSEX_STATUS_SINGLE;
- len--;
- }
- } else {
- if (xbuf[len - 1] == UMP_MIDI1_MSG_SYSEX_END) {
- status = UMP_SYSEX_STATUS_END;
- len--;
- } else {
- status = UMP_SYSEX_STATUS_CONTINUE;
- }
+ offset++;
+ xbuf++;
}
+
+ /* if the last of this packet or the 1st byte of the next packet
+ * is the end-marker, finish the transfer with this packet
+ */
+ if (len > 0 && len < 8 &&
+ xbuf[len - 1] == UMP_MIDI1_MSG_SYSEX_END) {
+ if (status == UMP_SYSEX_STATUS_START)
+ status = UMP_SYSEX_STATUS_SINGLE;
+ else
+ status = UMP_SYSEX_STATUS_END;
+ len--;
+ finished = true;
+ }
+
+ len = min(len, 6);
fill_sysex7_ump(dest_port, ev_cvt.ump, status, xbuf, len);
err = __snd_seq_deliver_single_event(dest, dest_port,
(struct snd_seq_event *)&ev_cvt,
atomic, hop);
if (err < 0)
return err;
+ offset += len;
}
return 0;
}
--
2.46.0
