[ALSA] seq-midi - silently ignore non-MIDI events

ALSA sequencer
When non-MIDI sequencer events are sent to a RawMIDI port, silently
ignore them instead of returning a confusing error code which may upset
the sequencer and abort the current write() to /dev/snd/seq.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

1 files changed, 6 insertions, 10 deletions

diff --git a/sound/core/seq/seq_midi.c b/sound/core/seq/seq_midi.c
index 57be9155eb62..4374829ea770 100644
--- a/sound/core/seq/seq_midi.c
+++ b/sound/core/seq/seq_midi.c
@@ -134,7 +134,7 @@ static int event_process_midi(snd_seq_event_t * ev, int direct,
         seq_midisynth_t *msynth = (seq_midisynth_t *) private_data;
         unsigned char msg[10];  /* buffer for constructing midi messages */
         snd_rawmidi_substream_t *substream;
-        int res;
+        int len;
 
         snd_assert(msynth != NULL, return -EINVAL);
         substream = msynth->output_rfile.output;
@@ -146,20 +146,16 @@ static int event_process_midi(snd_seq_event_t * ev, int direct,
                         snd_printd("seq_midi: invalid sysex event flags = 0x%x\n", ev->flags);
                         return 0;
                 }
-                res = snd_seq_dump_var_event(ev, (snd_seq_dump_func_t)dump_midi, substream);
+                snd_seq_dump_var_event(ev, (snd_seq_dump_func_t)dump_midi, substream);
                 snd_midi_event_reset_decode(msynth->parser);
-                if (res < 0)
-                        return res;
         } else {
                 if (msynth->parser == NULL)
                         return -EIO;
-                res = snd_midi_event_decode(msynth->parser, msg, sizeof(msg), ev);
-                if (res < 0)
-                        return res;
-                if ((res = dump_midi(substream, msg, res)) < 0) {
+                len = snd_midi_event_decode(msynth->parser, msg, sizeof(msg), ev);
+                if (len < 0)
+                        return 0;
+                if (dump_midi(substream, msg, len) < 0)
                         snd_midi_event_reset_decode(msynth->parser);
-                        return res;
-                }
         }
         return 0;
 }