diff -r 3b8e4ee4363e alsactl/state.c
--- a/alsactl/state.c	Mon Oct 15 10:36:47 2007 +0200
+++ b/alsactl/state.c	Fri Oct 26 02:01:44 2007 +0200
@@ -188,6 +188,46 @@ static unsigned int *str_to_tlv(const ch
 	return tlv;
 }
 
+/*
+ * add the TLV string and dB ranges to comment fields
+ */
+static int add_tlv_comments(snd_ctl_t *handle, snd_ctl_elem_id_t *id,
+			    snd_ctl_elem_info_t *info, snd_config_t *comment)
+{
+	unsigned int tlv[MAX_USER_TLV_SIZE];
+	unsigned int *db;
+	long dbmin, dbmax;
+	int err;
+
+	if (snd_ctl_elem_tlv_read(handle, id, tlv, sizeof(tlv)) < 0)
+		return 0; /* ignore error */
+
+	if (snd_ctl_elem_info_is_tlv_writable(info)) {
+		char *s = tlv_to_str(tlv);
+		if (s) {
+			err = snd_config_string_add(comment, "tlv", s);
+			if (err < 0) {
+				error("snd_config_string_add: %s", snd_strerror(err));
+				return err;
+			}
+			free(s);
+		}
+	}
+
+	err = snd_tlv_parse_dB_info(tlv, sizeof(tlv), &db);
+	if (err <= 0)
+		return 0;
+
+	snd_tlv_get_dB_range(db, snd_ctl_elem_info_get_min(info),
+			     snd_ctl_elem_info_get_max(info),
+			     &dbmin, &dbmax);
+	if (err < 0)
+		return err;
+	snd_config_integer_add(comment, "dbmin", dbmin);
+	snd_config_integer_add(comment, "dbmax", dbmax);
+	return 0;
+}
+
 static int get_control(snd_ctl_t *handle, snd_ctl_elem_id_t *id, snd_config_t *top)
 {
 	snd_ctl_elem_value_t *ctl;
@@ -285,8 +325,12 @@ static int get_control(snd_ctl_t *handle
 			error("snd_config_string_add: %s", snd_strerror(err));
 			return err;
 		}
-		if (snd_ctl_elem_info_is_tlv_readable(info) &&
-		    snd_ctl_elem_info_is_tlv_writable(info)) {
+		if (snd_ctl_elem_info_is_tlv_readable(info)) {
+			err = add_tlv_comments(handle, id, info, comment);
+			if (err < 0)
+				return err;
+		}
+		if (snd_ctl_elem_info_is_tlv_readable(info)) {
 			unsigned int tlv[MAX_USER_TLV_SIZE];
 			err = snd_ctl_elem_tlv_read(handle, id, tlv, sizeof(tlv));
 			if (err >= 0) {
@@ -651,6 +695,7 @@ static int config_bool(snd_config_t *n)
 	const char *str;
 	long val;
 	long long lval;
+
 	switch (snd_config_get_type(n)) {
 	case SND_CONFIG_TYPE_INTEGER:
 		snd_config_get_integer(n, &val);
@@ -665,6 +710,11 @@ static int config_bool(snd_config_t *n)
 	case SND_CONFIG_TYPE_STRING:
 		snd_config_get_string(n, &str);
 		break;
+	case SND_CONFIG_TYPE_COMPOUND:
+		if (!force_restore)
+			return -1;
+		n = snd_config_iterator_entry(snd_config_iterator_first(n));
+		return config_bool(n);
 	default:
 		return -1;
 	}
@@ -682,6 +732,7 @@ static int config_enumerated(snd_config_
 	long val;
 	long long lval;
 	unsigned int idx, items;
+
 	switch (snd_config_get_type(n)) {
 	case SND_CONFIG_TYPE_INTEGER:
 		snd_config_get_integer(n, &val);
@@ -692,6 +743,11 @@ static int config_enumerated(snd_config_
 	case SND_CONFIG_TYPE_STRING:
 		snd_config_get_string(n, &str);
 		break;
+	case SND_CONFIG_TYPE_COMPOUND:
+		if (!force_restore)
+			return -1;
+		n = snd_config_iterator_entry(snd_config_iterator_first(n));
+		return config_enumerated(n, handle, info);
 	default:
 		return -1;
 	}
@@ -708,6 +764,30 @@ static int config_enumerated(snd_config_
 			return idx;
 	}
 	return -1;
+}
+
+static int config_integer(snd_config_t *n, long *val)
+{
+	int err = snd_config_get_integer(n, val);
+	if (err < 0 && force_restore) {
+		if (snd_config_get_type(n) != SND_CONFIG_TYPE_COMPOUND)
+			return err;
+		n = snd_config_iterator_entry(snd_config_iterator_first(n));
+		return config_integer(n, val);
+	}
+	return err;
+}
+
+static int config_integer64(snd_config_t *n, long long *val)
+{
+	int err = snd_config_get_integer64(n, val);
+	if (err < 0 && force_restore) {
+		if (snd_config_get_type(n) != SND_CONFIG_TYPE_COMPOUND)
+			return err;
+		n = snd_config_iterator_entry(snd_config_iterator_first(n));
+		return config_integer64(n, val);
+	}
+	return err;
 }
 
 static int is_user_control(snd_config_t *conf)
@@ -729,6 +809,56 @@ static int is_user_control(snd_config_t 
 	return 0;
 }
 
+/*
+ * get the item type from the given comment config
+ */
+static int get_comment_type(snd_config_t *n)
+{
+	const char *type;
+
+	if (snd_config_get_string(n, &type) < 0)
+		return -EINVAL;
+	if (strcmp(type, "BOOLEAN") == 0)
+		return SND_CTL_ELEM_TYPE_BOOLEAN;
+	else if (strcmp(type, "INTEGER") == 0)
+		return SND_CTL_ELEM_TYPE_INTEGER;
+	else if (strcmp(type, "ENUMERATED") == 0)
+		return SND_CTL_ELEM_TYPE_ENUMERATED;
+	else if (strcmp(type, "INTEGER64") == 0)
+		return SND_CTL_ELEM_TYPE_INTEGER;
+	else if (strcmp(type, "IEC958") == 0)
+		return SND_CTL_ELEM_TYPE_IEC958;
+	else
+		return -EINVAL;
+}
+
+/*
+ * get the value range from the given comment config
+ */
+static int get_comment_range(snd_config_t *n, int ctype,
+			     long *imin, long *imax, long *istep)
+{
+	const char *s;
+	int err;
+
+	if (snd_config_get_string(n, &s) < 0)
+		return -EINVAL;
+	switch (ctype) {
+	case SND_CTL_ELEM_TYPE_INTEGER:
+		err = sscanf(s, "%li - %li (step %li)", imin, imax, istep);
+		if (err != 3) {
+			istep = 0;
+			err = sscanf(s, "%li - %li", imin, imax);
+			if (err != 2)
+				return -EINVAL;
+		}
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
 static int add_user_control(snd_ctl_t *handle, snd_ctl_elem_info_t *info, snd_config_t *conf)
 {
 	snd_ctl_elem_id_t *id;
@@ -745,39 +875,20 @@ static int add_user_control(snd_ctl_t *h
 	tlv = NULL;
 	snd_config_for_each(i, next, conf) {
 		snd_config_t *n = snd_config_iterator_entry(i);
-		const char *id, *type;
+		const char *id;
 		if (snd_config_get_id(n, &id) < 0)
 			continue;
 		if (strcmp(id, "type") == 0) {
-			if ((err = snd_config_get_string(n, &type)) < 0)
-				return -EINVAL;
-			if (strcmp(type, "BOOLEAN") == 0)
-				ctype = SND_CTL_ELEM_TYPE_BOOLEAN;
-			else if (strcmp(type, "INTEGER") == 0)
-				ctype = SND_CTL_ELEM_TYPE_INTEGER;
-			else if (strcmp(type, "IEC958") == 0)
-				ctype = SND_CTL_ELEM_TYPE_IEC958;
-			else
-				return -EINVAL;
+			err = get_comment_type(n);
+			if (err < 0)
+				return err;
+			ctype = err;
 			continue;
 		}
 		if (strcmp(id, "range") == 0) {
-			const char *s;
-			if ((err = snd_config_get_string(n, &s)) < 0)
-				return -EINVAL;
-			switch (ctype) {
-			case SND_CTL_ELEM_TYPE_INTEGER:
-				err = sscanf(s, "%li - %li (step %li)", &imin, &imax, &istep);
-				if (err != 3) {
-					istep = 0;
-					err = sscanf(s, "%li - %li", &imin, &imax);
-					if (err != 2)
-						return -EINVAL;
-				}
-				break;
-			default:
-				return -EINVAL;
-			}
+			err = get_comment_range(n, ctype, &imin, &imax, &istep);
+			if (err < 0)
+				return err;
 			continue;
 		}
 		if (strcmp(id, "count") == 0) {
@@ -831,6 +942,213 @@ static int add_user_control(snd_ctl_t *h
 	return snd_ctl_elem_info(handle, info);
 }
 
+/*
+ * look for a config node with the given item name
+ */
+static snd_config_t *search_comment_item(snd_config_t *conf, const char *name)
+{
+	snd_config_iterator_t i, next;
+	snd_config_for_each(i, next, conf) {
+		snd_config_t *n = snd_config_iterator_entry(i);
+		const char *id;
+		if (snd_config_get_id(n, &id) < 0)
+			continue;
+		if (strcmp(id, name) == 0)
+			return n;
+	}
+	return NULL;
+}
+
+/*
+ * check whether the config item has the same of compatible type
+ */
+static int check_comment_type(snd_config_t *conf, int type)
+{
+	snd_config_t *n = search_comment_item(conf, "type");
+	int ctype;
+
+	if (!n)
+		return 0; /* not defined */
+	ctype = get_comment_type(n);
+	if (ctype == type)
+		return 0;
+	if ((ctype == SND_CTL_ELEM_TYPE_BOOLEAN ||
+	     ctype == SND_CTL_ELEM_TYPE_INTEGER ||
+	     ctype == SND_CTL_ELEM_TYPE_INTEGER64 ||
+	     ctype == SND_CTL_ELEM_TYPE_ENUMERATED) &&
+	    (type == SND_CTL_ELEM_TYPE_BOOLEAN ||
+	     type == SND_CTL_ELEM_TYPE_INTEGER ||
+	     type == SND_CTL_ELEM_TYPE_INTEGER64 ||
+	     type == SND_CTL_ELEM_TYPE_ENUMERATED))
+		return 0; /* OK, compatible */
+	return -EINVAL;
+}
+
+/*
+ * convert from an old value to a new value with the same dB level
+ */
+static int convert_to_new_db(snd_config_t *value, long omin, long omax,
+			     long nmin, long nmax,
+			     long odbmin, long odbmax,
+			     long ndbmin, long ndbmax)
+{
+	long val;
+	if (config_integer(value, &val) < 0)
+		return -EINVAL;
+	if (val < omin || val > omax)
+		return -EINVAL;
+	val = ((val - omin) * (odbmax - odbmin)) / (omax - omin) + odbmin;
+	if (val < ndbmin)
+		val = ndbmin;
+	else if (val > ndbmax)
+		val = ndbmax;
+	val = ((val - ndbmin) * (nmax - nmin)) / (ndbmax - ndbmin) + nmin;
+	return snd_config_set_integer(value, val);
+}
+
+/*
+ * compare the current value range with the old range in comments.
+ * also, if dB information is available, try to compare them.
+ * if any change occurs, try to keep the same dB level.
+ */
+static int check_comment_range(snd_ctl_t *handle, snd_config_t *conf,
+			       snd_ctl_elem_info_t *info, snd_config_t *value)
+{
+	snd_config_t *n;
+	long omin, omax, ostep;
+	long nmin, nmax;
+	long odbmin, odbmax;
+	long ndbmin, ndbmax;
+	snd_ctl_elem_id_t *id;
+
+	n = search_comment_item(conf, "range");
+	if (!n)
+		return 0;
+	if (get_comment_range(n, SND_CTL_ELEM_TYPE_INTEGER,
+			      &omin, &omax, &ostep) < 0)
+		return 0;
+	nmin = snd_ctl_elem_info_get_min(info);
+	nmax = snd_ctl_elem_info_get_max(info);
+	if (omin != nmin && omax != nmax) {
+		/* Hey, the range mismatches */
+		if (!force_restore)
+			return -EINVAL;
+	}
+	if (omin >= omax || nmin >= nmax)
+		return 0; /* invalid values */
+
+	n = search_comment_item(conf, "dbmin");
+	if (!n)
+		return 0;
+	if (config_integer(n, &odbmin) < 0)
+		return 0;
+	n = search_comment_item(conf, "dbmax");
+	if (!n)
+		return 0;
+	if (config_integer(n, &odbmax) < 0)
+		return 0;
+	if (odbmin >= odbmax)
+		return 0; /* invalid values */
+	snd_ctl_elem_id_alloca(&id);
+	snd_ctl_elem_info_get_id(info, id);
+	if (snd_ctl_get_dB_range(handle, id, &ndbmin, &ndbmax) < 0)
+		return 0;
+	if (ndbmin >= ndbmax)
+		return 0; /* invalid values */
+	if (omin == nmin && omax == nmax &&
+	    odbmin == ndbmin && odbmax == ndbmax)
+		return 0; /* OK, identical one */
+
+	/* Let's guess the current value from dB range */
+	if (snd_config_get_type(value) == SND_CONFIG_TYPE_COMPOUND) {
+		snd_config_iterator_t i, next;
+		snd_config_for_each(i, next, value) {
+			snd_config_t *n = snd_config_iterator_entry(i);
+			convert_to_new_db(n, omin, omax, nmin, nmax,
+					  odbmin, odbmax, ndbmin, ndbmax);
+		}
+	} else
+		convert_to_new_db(value, omin, omax, nmin, nmax,
+				  odbmin, odbmax, ndbmin, ndbmax);
+	return 0;
+}
+
+static int restore_config_value(snd_ctl_t *handle, snd_ctl_elem_info_t *info,
+				snd_ctl_elem_iface_t type,
+				snd_config_t *value,
+				snd_ctl_elem_value_t *ctl, int idx)
+{
+	long val;
+	long long lval;
+	int err;
+
+	switch (type) {
+	case SND_CTL_ELEM_TYPE_BOOLEAN:
+		val = config_bool(value);
+		if (val >= 0) {
+			snd_ctl_elem_value_set_boolean(ctl, idx, val);
+			return 1;
+		}
+		break;
+	case SND_CTL_ELEM_TYPE_INTEGER:
+		err = config_integer(value, &val);
+		if (err == 0) {
+			snd_ctl_elem_value_set_integer(ctl, idx, val);
+			return 1;
+		}
+		break;
+	case SND_CTL_ELEM_TYPE_INTEGER64:
+		err = config_integer64(value, &lval);
+		if (err == 0) {
+			snd_ctl_elem_value_set_integer64(ctl, idx, lval);
+			return 1;
+		}
+		break;
+	case SND_CTL_ELEM_TYPE_ENUMERATED:
+		val = config_enumerated(value, handle, info);
+		if (val >= 0) {
+			snd_ctl_elem_value_set_enumerated(ctl, idx, val);
+			return 1;
+		}
+		break;
+	case SND_CTL_ELEM_TYPE_BYTES:
+	case SND_CTL_ELEM_TYPE_IEC958:
+		break;
+	default:
+		error("Unknow control type: %d", type);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int restore_config_value2(snd_ctl_t *handle, snd_ctl_elem_info_t *info,
+				 snd_ctl_elem_iface_t type,
+				 snd_config_t *value,
+				 snd_ctl_elem_value_t *ctl, int idx,
+				 unsigned int numid)
+{
+	int err = restore_config_value(handle, info, type, value, ctl, idx);
+	long val;
+
+	if (err != 0)
+		return err;
+	switch (type) {
+	case SND_CTL_ELEM_TYPE_BYTES:
+	case SND_CTL_ELEM_TYPE_IEC958:
+		err = snd_config_get_integer(value, &val);
+		if (err < 0 || val < 0 || val > 255) {
+			error("bad control.%d.value.%d content", numid, idx);
+			return force_restore ? 0 : -EINVAL;
+		}
+		snd_ctl_elem_value_set_byte(ctl, idx, val);
+		return 1;
+		break;
+	default:
+		break;
+	}
+	return 0;
+}
+
 static int set_control(snd_ctl_t *handle, snd_config_t *control)
 {
 	snd_ctl_elem_value_t *ctl;
@@ -852,8 +1170,6 @@ static int set_control(snd_ctl_t *handle
 	long index = -1;
 	snd_config_t *value = NULL;
 	snd_config_t *comment = NULL;
-	long val;
-	long long lval;
 	unsigned int idx;
 	int err;
 	char *set;
@@ -994,56 +1310,28 @@ static int set_control(snd_ctl_t *handle
 		return -ENOENT;
 	}
 
-#if 0
 	if (comment) {
-		check_comment_type(comment, type);
-		if (type == SND_CTL_ELEM_TYPE_INTEGER ||
-		    type == SND_CTL_ELEM_TYPE_INTEGER64)
-			check_comment_range(comment, info);
+		if (check_comment_type(comment, type) < 0)
+			error("incompatible field type for control #%d", numid);
+		if (type == SND_CTL_ELEM_TYPE_INTEGER) {
+			if (check_comment_range(handle, comment, info, value) < 0) {
+				error("value range mismatch for control #%d",
+				      numid);
+				return -EINVAL;
+			}
+		}
 	}
-#endif
 
 	if (!snd_ctl_elem_info_is_writable(info))
 		return 0;
 	snd_ctl_elem_value_set_numid(ctl, numid1);
 
 	if (count == 1) {
-		switch (type) {
-		case SND_CTL_ELEM_TYPE_BOOLEAN:
-			val = config_bool(value);
-			if (val >= 0) {
-				snd_ctl_elem_value_set_boolean(ctl, 0, val);
-				goto _ok;
-			}
-			break;
-		case SND_CTL_ELEM_TYPE_INTEGER:
-			err = snd_config_get_integer(value, &val);
-			if (err == 0) {
-				snd_ctl_elem_value_set_integer(ctl, 0, val);
-				goto _ok;
-			}
-			break;
-		case SND_CTL_ELEM_TYPE_INTEGER64:
-			err = snd_config_get_integer64(value, &lval);
-			if (err == 0) {
-				snd_ctl_elem_value_set_integer64(ctl, 0, lval);
-				goto _ok;
-			}
-			break;
-		case SND_CTL_ELEM_TYPE_ENUMERATED:
-			val = config_enumerated(value, handle, info);
-			if (val >= 0) {
-				snd_ctl_elem_value_set_enumerated(ctl, 0, val);
-				goto _ok;
-			}
-			break;
-		case SND_CTL_ELEM_TYPE_BYTES:
-		case SND_CTL_ELEM_TYPE_IEC958:
-			break;
-		default:
-			error("Unknow control type: %d", type);
-			return -EINVAL;
-		}
+		err = restore_config_value(handle, info, type, value, ctl, 0);
+		if (err < 0)
+			return err;
+		if (err > 0)
+			goto _ok;
 	}
 	switch (type) {
 	case SND_CTL_ELEM_TYPE_BYTES:
@@ -1080,8 +1368,17 @@ static int set_control(snd_ctl_t *handle
 		break;
 	}
 	if (snd_config_get_type(value) != SND_CONFIG_TYPE_COMPOUND) {
-		error("bad control.%d.value type", numid);
-		return -EINVAL;
+		if (!force_restore) {
+			error("bad control.%d.value type", numid);
+			return -EINVAL;
+		}
+		for (idx = 0; idx < count; ++idx) {
+			err = restore_config_value2(handle, info, type, value,
+						    ctl, idx, numid);
+			if (err < 0)
+				return err;
+		}
+		goto _ok;
 	}
 
 	set = (char*) alloca(count);
@@ -1095,59 +1392,22 @@ static int set_control(snd_ctl_t *handle
 		if (idx < 0 || idx >= count || 
 		    set[idx]) {
 			error("bad control.%d.value index", numid);
-			return -EINVAL;
+			if (!force_restore)
+				return -EINVAL;
+			continue;
 		}
-		switch (type) {
-		case SND_CTL_ELEM_TYPE_BOOLEAN:
-			val = config_bool(n);
-			if (val < 0) {
-				error("bad control.%d.value.%d content", numid, idx);
-				return -EINVAL;
-			}
-			snd_ctl_elem_value_set_boolean(ctl, idx, val);
-			break;
-		case SND_CTL_ELEM_TYPE_INTEGER:
-			err = snd_config_get_integer(n, &val);
-			if (err < 0) {
-				error("bad control.%d.value.%d content", numid, idx);
-				return -EINVAL;
-			}
-			snd_ctl_elem_value_set_integer(ctl, idx, val);
-			break;
-		case SND_CTL_ELEM_TYPE_INTEGER64:
-			err = snd_config_get_integer64(n, &lval);
-			if (err < 0) {
-				error("bad control.%d.value.%d content", numid, idx);
-				return -EINVAL;
-			}
-			snd_ctl_elem_value_set_integer64(ctl, idx, lval);
-			break;
-		case SND_CTL_ELEM_TYPE_ENUMERATED:
-			val = config_enumerated(n, handle, info);
-			if (val < 0) {
-				error("bad control.%d.value.%d content", numid, idx);
-				return -EINVAL;
-			}
-			snd_ctl_elem_value_set_enumerated(ctl, idx, val);
-			break;
-		case SND_CTL_ELEM_TYPE_BYTES:
-		case SND_CTL_ELEM_TYPE_IEC958:
-			err = snd_config_get_integer(n, &val);
-			if (err < 0 || val < 0 || val > 255) {
-				error("bad control.%d.value.%d content", numid, idx);
-				return -EINVAL;
-			}
-			snd_ctl_elem_value_set_byte(ctl, idx, val);
-			break;
-		default:
-			break;
-		}
-		set[idx] = 1;
+		err = restore_config_value2(handle, info, type, value,
+					    ctl, idx, numid);
+		if (err < 0)
+			return err;
+		if (err > 0)
+			set[idx] = 1;
 	}
 	for (idx = 0; idx < count; ++idx) {
 		if (!set[idx]) {
 			error("control.%d.value.%d is not specified", numid, idx);
-			return -EINVAL;
+			if (!force_restore)
+				return -EINVAL;
 		}
 	}
 
diff -r 3b8e4ee4363e configure.in
--- a/configure.in	Mon Oct 15 10:36:47 2007 +0200
+++ b/configure.in	Fri Oct 26 02:01:44 2007 +0200
@@ -27,7 +27,9 @@ dnl AC_PROG_CXX
 dnl AC_PROG_CXX
 AC_PROG_INSTALL
 AC_PROG_LN_S
-AM_PATH_ALSA(1.0.12)
+AM_PATH_ALSA(1.0.15)
+AC_CHECK_FUNC(snd_tlv_get_dB_range,,
+	AC_ERROR([No TLV support code in alsa-lib]))
 
 AC_ARG_ENABLE(alsamixer,
      [  --disable-alsamixer     Disable alsamixer compilation],
diff -r 3b8e4ee4363e seq/aseqnet/aseqnet.c
--- a/seq/aseqnet/aseqnet.c	Mon Oct 15 10:36:47 2007 +0200
+++ b/seq/aseqnet/aseqnet.c	Fri Oct 26 02:01:44 2007 +0200
@@ -26,6 +26,7 @@
 #include <alsa/asoundlib.h>
 #include <getopt.h>
 #include <signal.h>
+#include <assert.h>
 #include "aconfig.h"
 #include "gettext.h"