@@ -55,7 +55,6 @@ struct seq_oss_chinfo {
struct seq_oss_synthinfo {
struct snd_seq_oss_arg arg;
struct seq_oss_chinfo *ch;
- struct seq_oss_synth_sysex *sysex;
int nr_voices;
int opened;
int is_midi;
@@ -26,13 +26,6 @@
* definition of synth info records
*/
-/* sysex buffer */
-struct seq_oss_synth_sysex {
- int len;
- int skip;
- unsigned char buf[MAX_SYSEX_BUFLEN];
-};
-
/* synth info */
struct seq_oss_synth {
int seq_device;
@@ -66,7 +59,6 @@ static struct seq_oss_synth midi_synth_dev = {
};
static DEFINE_SPINLOCK(register_lock);
-static DEFINE_MUTEX(sysex_mutex);
/*
* prototypes
@@ -319,8 +311,6 @@ snd_seq_oss_synth_cleanup(struct seq_oss_devinfo *dp)
}
snd_use_lock_free(&rec->use_lock);
}
- kfree(info->sysex);
- info->sysex = NULL;
kfree(info->ch);
info->ch = NULL;
}
@@ -396,8 +386,6 @@ snd_seq_oss_synth_reset(struct seq_oss_devinfo *dp, int dev)
info = get_synthinfo_nospec(dp, dev);
if (!info || !info->opened)
return;
- if (info->sysex)
- info->sysex->len = 0; /* reset sysex */
reset_channels(info);
if (info->is_midi) {
if (midi_synth_dev.opened <= 0)
@@ -409,8 +397,6 @@ snd_seq_oss_synth_reset(struct seq_oss_devinfo *dp, int dev)
dp->file_mode) < 0) {
midi_synth_dev.opened--;
info->opened = 0;
- kfree(info->sysex);
- info->sysex = NULL;
kfree(info->ch);
info->ch = NULL;
}
@@ -483,64 +469,26 @@ snd_seq_oss_synth_info(struct seq_oss_devinfo *dp, int dev)
/*
* receive OSS 6 byte sysex packet:
- * the full sysex message will be sent if it reaches to the end of data
- * (0xff).
+ * the event is filled and prepared for sending immediately
+ * (i.e. sysex messages are fragmented)
*/
int
snd_seq_oss_synth_sysex(struct seq_oss_devinfo *dp, int dev, unsigned char *buf, struct snd_seq_event *ev)
{
- int i, send;
- unsigned char *dest;
- struct seq_oss_synth_sysex *sysex;
- struct seq_oss_synthinfo *info;
+ unsigned char *p;
+ int len = 6;
- info = snd_seq_oss_synth_info(dp, dev);
- if (!info)
- return -ENXIO;
+ p = memchr(buf, 0xff, 6);
+ if (p)
+ len = p - buf + 1;
- guard(mutex)(&sysex_mutex);
- sysex = info->sysex;
- if (sysex == NULL) {
- sysex = kzalloc(sizeof(*sysex), GFP_KERNEL);
- if (sysex == NULL)
- return -ENOMEM;
- info->sysex = sysex;
- }
-
- send = 0;
- dest = sysex->buf + sysex->len;
- /* copy 6 byte packet to the buffer */
- for (i = 0; i < 6; i++) {
- if (buf[i] == 0xff) {
- send = 1;
- break;
- }
- dest[i] = buf[i];
- sysex->len++;
- if (sysex->len >= MAX_SYSEX_BUFLEN) {
- sysex->len = 0;
- sysex->skip = 1;
- break;
- }
- }
-
- if (sysex->len && send) {
- if (sysex->skip) {
- sysex->skip = 0;
- sysex->len = 0;
- return -EINVAL; /* skip */
- }
- /* copy the data to event record and send it */
- ev->flags = SNDRV_SEQ_EVENT_LENGTH_VARIABLE;
- if (snd_seq_oss_synth_addr(dp, dev, ev))
- return -EINVAL;
- ev->data.ext.len = sysex->len;
- ev->data.ext.ptr = sysex->buf;
- sysex->len = 0;
- return 0;
- }
-
- return -EINVAL; /* skip */
+ /* copy the data to event record and send it */
+ if (snd_seq_oss_synth_addr(dp, dev, ev))
+ return -EINVAL;
+ ev->flags = SNDRV_SEQ_EVENT_LENGTH_VARIABLE;
+ ev->data.ext.len = len;
+ ev->data.ext.ptr = buf;
+ return 0;
}
/*
The recent bug report spotted on the old OSS sequencer code that tries to combine incoming SysEx messages to a single sequencer event. This is good, per se, but it has more demerits: - The sysex message delivery is delayed until the very last event - The use of internal buffer forced the serialization The recent fix in commit 0179488ca992 ("ALSA: seq: oss: Fix races at processing SysEx messages") addressed the latter, but a better fix is to handle the sysex messages immediately, i.e. just send each incoming fragmented sysex message as is. And this patch implements that. This resulted in a significant cleanup as well. Note that the only caller of snd_seq_oss_synth_sysex() is snd_seq_oss_process_event(), and all its callers dispatch the event immediately, so we can just put the passed buffer pointer to the event record to be handled. Reported-and-tested-by: Kun Hu <huk23@m.fudan.edu.cn> Link: https://lore.kernel.org/2B7E93E4-B13A-4AE4-8E87-306A8EE9BBB7@m.fudan.edu.cn Signed-off-by: Takashi Iwai <tiwai@suse.de> --- sound/core/seq/oss/seq_oss_device.h | 1 - sound/core/seq/oss/seq_oss_synth.c | 80 +++++------------------------ 2 files changed, 14 insertions(+), 67 deletions(-)