sys/dev/sound/pcm/sndstat.c:

   * General spl* cleanup. It doesn't serve any purpose anymore.
   * Nuke sndstat_busy(). Addition of sndstat_acquire() /
     sndstat_release() for sndstat exclusive access. [1]

sys/dev/sound/pcm/sound.c:
   * Remove duplicate SLIST_INIT()
   * Use sndstat_acquire() / release() to lock / release the entire
     sndstat during pcm_unregister(). This should fix LOR #159 [1]

sys/dev/sound/pcm/sound.h:
   * Definition of SD_F_SOFTVOL (part of feeder volume)
   * Nuke sndstat_busy(). Addition of sndstat_acquire() /
     sndstat_release() for exclusive sndstat access. [1]

Submitted by:	Ariff Abdullah <skywizard@MyBSD.org.my>
LOR:		159 [1]
Discussed with:	yongari [1]

3 files changed, 42 insertions, 51 deletions

diff --git a/sys/dev/sound/pcm/sndstat.c b/sys/dev/sound/pcm/sndstat.c
index 5ccf0b7..5b07ece 100644
--- a/sys/dev/sound/pcm/sndstat.c
+++ b/sys/dev/sound/pcm/sndstat.c
@@ -84,20 +84,17 @@ static int sndstat_prepare(struct sbuf *s);
 static int
 sysctl_hw_sndverbose(SYSCTL_HANDLER_ARGS)
 {
-	intrmask_t s;
 	int error, verbose;
 
 	verbose = sndstat_verbose;
 	error = sysctl_handle_int(oidp, &verbose, sizeof(verbose), req);
 	if (error == 0 && req->newptr != NULL) {
-		s = spltty();
 		sx_xlock(&sndstat_lock);
 		if (verbose < 0 || verbose > 3)
 			error = EINVAL;
 		else
 			sndstat_verbose = verbose;
 		sx_xunlock(&sndstat_lock);
-		splx(s);
 	}
 	return error;
 }
@@ -107,19 +104,15 @@ SYSCTL_PROC(_hw_snd, OID_AUTO, verbose, CTLTYPE_INT | CTLFLAG_RW,
 static int
 sndstat_open(struct cdev *i_dev, int flags, int mode, struct thread *td)
 {
-	intrmask_t s;
 	int error;
 
-	s = spltty();
 	sx_xlock(&sndstat_lock);
 	if (sndstat_isopen) {
 		sx_xunlock(&sndstat_lock);
-		splx(s);
 		return EBUSY;
 	}
 	sndstat_isopen = 1;
 	sx_xunlock(&sndstat_lock);
-	splx(s);
 	if (sbuf_new(&sndstat_sbuf, NULL, 4096, 0) == NULL) {
 		error = ENXIO;
 		goto out;
@@ -128,11 +121,9 @@ sndstat_open(struct cdev *i_dev, int flags, int mode, struct thread *td)
 	error = (sndstat_prepare(&sndstat_sbuf) > 0) ? 0 : ENOMEM;
 out:
 	if (error) {
-		s = spltty();
 		sx_xlock(&sndstat_lock);
 		sndstat_isopen = 0;
 		sx_xunlock(&sndstat_lock);
-		splx(s);
 	}
 	return (error);
 }
@@ -140,34 +131,26 @@ out:
 static int
 sndstat_close(struct cdev *i_dev, int flags, int mode, struct thread *td)
 {
-	intrmask_t s;
-
-	s = spltty();
 	sx_xlock(&sndstat_lock);
 	if (!sndstat_isopen) {
 		sx_xunlock(&sndstat_lock);
-		splx(s);
 		return EBADF;
 	}
 	sbuf_delete(&sndstat_sbuf);
 	sndstat_isopen = 0;
 
 	sx_xunlock(&sndstat_lock);
-	splx(s);
 	return 0;
 }
 
 static int
 sndstat_read(struct cdev *i_dev, struct uio *buf, int flag)
 {
-	intrmask_t s;
 	int l, err;
 
-	s = spltty();
 	sx_xlock(&sndstat_lock);
 	if (!sndstat_isopen) {
 		sx_xunlock(&sndstat_lock);
-		splx(s);
 		return EBADF;
 	}
     	l = min(buf->uio_resid, sbuf_len(&sndstat_sbuf) - sndstat_bufptr);
@@ -175,7 +158,6 @@ sndstat_read(struct cdev *i_dev, struct uio *buf, int flag)
 	sndstat_bufptr += l;
 
 	sx_xunlock(&sndstat_lock);
-	splx(s);
 	return err;
 }
 
@@ -195,9 +177,34 @@ sndstat_find(int type, int unit)
 }
 
 int
+sndstat_acquire(void)
+{
+	sx_xlock(&sndstat_lock);
+	if (sndstat_isopen) {
+		sx_xunlock(&sndstat_lock);
+		return EBUSY;
+	}
+	sndstat_isopen = 1;
+	sx_xunlock(&sndstat_lock);
+	return 0;
+}
+
+int
+sndstat_release(void)
+{
+	sx_xlock(&sndstat_lock);
+	if (!sndstat_isopen) {
+		sx_xunlock(&sndstat_lock);
+		return EBADF;
+	}
+	sndstat_isopen = 0;
+	sx_xunlock(&sndstat_lock);
+	return 0;
+}
+
+int
 sndstat_register(device_t dev, char *str, sndstat_handler handler)
 {
-	intrmask_t s;
 	struct sndstat_entry *ent;
 	const char *devtype;
 	int type, unit;
@@ -228,14 +235,12 @@ sndstat_register(device_t dev, char *str, sndstat_handler handler)
 	ent->unit = unit;
 	ent->handler = handler;
 
-	s = spltty();
 	sx_xlock(&sndstat_lock);
 	SLIST_INSERT_HEAD(&sndstat_devlist, ent, link);
 	if (type == SS_TYPE_MODULE)
 		sndstat_files++;
 	sndstat_maxunit = (unit > sndstat_maxunit)? unit : sndstat_maxunit;
 	sx_xunlock(&sndstat_lock);
-	splx(s);
 
 	return 0;
 }
@@ -249,23 +254,19 @@ sndstat_registerfile(char *str)
 int
 sndstat_unregister(device_t dev)
 {
-	intrmask_t s;
 	struct sndstat_entry *ent;
 
-	s = spltty();
 	sx_xlock(&sndstat_lock);
 	SLIST_FOREACH(ent, &sndstat_devlist, link) {
 		if (ent->dev == dev) {
 			SLIST_REMOVE(&sndstat_devlist, ent, sndstat_entry, link);
 			sx_xunlock(&sndstat_lock);
-			splx(s);
 			free(ent, M_DEVBUF);
 
 			return 0;
 		}
 	}
 	sx_xunlock(&sndstat_lock);
-	splx(s);
 
 	return ENXIO;
 }
@@ -273,24 +274,20 @@ sndstat_unregister(device_t dev)
 int
 sndstat_unregisterfile(char *str)
 {
-	intrmask_t s;
 	struct sndstat_entry *ent;
 
-	s = spltty();
 	sx_xlock(&sndstat_lock);
 	SLIST_FOREACH(ent, &sndstat_devlist, link) {
 		if (ent->dev == NULL && ent->str == str) {
 			SLIST_REMOVE(&sndstat_devlist, ent, sndstat_entry, link);
 			sndstat_files--;
 			sx_xunlock(&sndstat_lock);
-			splx(s);
 			free(ent, M_DEVBUF);
 
 			return 0;
 		}
 	}
 	sx_xunlock(&sndstat_lock);
-	splx(s);
 
 	return ENXIO;
 }
@@ -353,13 +350,9 @@ sndstat_init(void)
 static int
 sndstat_uninit(void)
 {
-	intrmask_t s;
-
-	s = spltty();
 	sx_xlock(&sndstat_lock);
 	if (sndstat_isopen) {
 		sx_xunlock(&sndstat_lock);
-		splx(s);
 		return EBUSY;
 	}
 
@@ -367,18 +360,11 @@ sndstat_uninit(void)
 		destroy_dev(sndstat_dev);
 	sndstat_dev = 0;
 
-	splx(s);
 	sx_xunlock(&sndstat_lock);
 	sx_destroy(&sndstat_lock);
 	return 0;
 }
 
-int
-sndstat_busy(void)
-{
-	return (sndstat_isopen);
-}
-
 static void
 sndstat_sysinit(void *p)
 {
diff --git a/sys/dev/sound/pcm/sound.c b/sys/dev/sound/pcm/sound.c
index a5ce1d3..4a9b2f9 100644
--- a/sys/dev/sound/pcm/sound.c
+++ b/sys/dev/sound/pcm/sound.c
@@ -719,7 +719,6 @@ pcm_register(device_t dev, void *devinfo, int numplay, int numrec)
 	d->inprog = 0;
 
 	SLIST_INIT(&d->channels);
-	SLIST_INIT(&d->channels);
 
 	if (((numplay == 0) || (numrec == 0)) && (numplay != numrec))
 		d->flags |= SD_F_SIMPLEX;
@@ -758,24 +757,25 @@ pcm_unregister(device_t dev)
     	struct snddev_channel *sce;
 	struct pcm_channel *ch;
 
+	if (sndstat_acquire() != 0) {
+		device_printf(dev, "unregister: sndstat busy\n");
+		return EBUSY;
+	}
+
 	snd_mtxlock(d->lock);
 	if (d->inprog) {
 		device_printf(dev, "unregister: operation in progress\n");
 		snd_mtxunlock(d->lock);
-		return EBUSY;
-	}
-	if (sndstat_busy() != 0) {
-		device_printf(dev, "unregister: sndstat busy\n");
-		snd_mtxunlock(d->lock);
+		sndstat_release();
 		return EBUSY;
 	}
 
-
 	SLIST_FOREACH(sce, &d->channels, link) {
 		ch = sce->channel;
 		if (ch->refcount > 0) {
 			device_printf(dev, "unregister: channel %s busy (pid %d)\n", ch->name, ch->pid);
 			snd_mtxunlock(d->lock);
+			sndstat_release();
 			return EBUSY;
 		}
 	}
@@ -783,6 +783,7 @@ pcm_unregister(device_t dev)
 	if (mixer_uninit(dev)) {
 		device_printf(dev, "unregister: mixer busy\n");
 		snd_mtxunlock(d->lock);
+		sndstat_release();
 		return EBUSY;
 	}
 
@@ -807,9 +808,10 @@ pcm_unregister(device_t dev)
 	chn_kill(d->fakechan);
 	fkchan_kill(d->fakechan);
 
-	sndstat_unregister(dev);
 	snd_mtxunlock(d->lock);
 	snd_mtxfree(d->lock);
+	sndstat_unregister(dev);
+	sndstat_release();
 	return 0;
 }
 
@@ -905,7 +907,8 @@ sndstat_prepare_pcm(struct sbuf *s, device_t dev, int verbose)
 					sbuf_printf(s, "(0x%08x -> 0x%08x)", f->desc->in, f->desc->out);
 				if (f->desc->type == FEEDER_RATE)
 					sbuf_printf(s, "(%d -> %d)", FEEDER_GET(f, FEEDRATE_SRC), FEEDER_GET(f, FEEDRATE_DST));
-				if (f->desc->type == FEEDER_ROOT || f->desc->type == FEEDER_MIXER)
+				if (f->desc->type == FEEDER_ROOT || f->desc->type == FEEDER_MIXER ||
+						f->desc->type == FEEDER_VOLUME)
 					sbuf_printf(s, "(0x%08x)", f->desc->out);
 				sbuf_printf(s, " -> ");
 				f = f->parent;
diff --git a/sys/dev/sound/pcm/sound.h b/sys/dev/sound/pcm/sound.h
index 471e51d..af539a6 100644
--- a/sys/dev/sound/pcm/sound.h
+++ b/sys/dev/sound/pcm/sound.h
@@ -130,7 +130,8 @@ nomenclature:
 #define PCMMKMINOR(u, d, c) ((((c) & 0xff) << 16) | (((u) & 0x0f) << 4) | ((d) & 0x0f))
 
 #define SD_F_SIMPLEX		0x00000001
-#define	SD_F_AUTOVCHAN		0x00000002
+#define SD_F_AUTOVCHAN		0x00000002
+#define SD_F_SOFTVOL		0x00000004
 #define SD_F_PRIO_RD		0x10000000
 #define SD_F_PRIO_WR		0x20000000
 #define SD_F_PRIO_SET		(SD_F_PRIO_RD | SD_F_PRIO_WR)
@@ -238,11 +239,12 @@ void snd_mtxassert(void *m);
 int sysctl_hw_snd_vchans(SYSCTL_HANDLER_ARGS);
 
 typedef int (*sndstat_handler)(struct sbuf *s, device_t dev, int verbose);
+int sndstat_acquire(void);
+int sndstat_release(void);
 int sndstat_register(device_t dev, char *str, sndstat_handler handler);
 int sndstat_registerfile(char *str);
 int sndstat_unregister(device_t dev);
 int sndstat_unregisterfile(char *str);
-int sndstat_busy(void);
 
 #define SND_DECLARE_FILE(version) \
 	_SND_DECLARE_FILE(__LINE__, version)