[ALSA] seq: reorganize sequencer client numbers

Modules: ALSA sequencer

Reduce the maximum possible number of global clients to 16 to make
more numbers available for card clients, and allow dynamically allocated
card client numbers to share the same range as application client
numbers to make sure that all 32 cards can be used at the same time.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

include/sound/asequencer.h

@@ -502,8 +502,9 @@ struct snd_seq_running_info {
 
 	/* known client numbers */
 #define SNDRV_SEQ_CLIENT_SYSTEM		0
-#define SNDRV_SEQ_CLIENT_DUMMY		62	/* dummy ports */
-#define SNDRV_SEQ_CLIENT_OSS		63	/* oss sequencer emulator */
+	/* internal client numbers */
+#define SNDRV_SEQ_CLIENT_DUMMY		14	/* midi through */
+#define SNDRV_SEQ_CLIENT_OSS		15	/* oss sequencer emulator */
 
 
 	/* client types */

sound/core/seq/seq.c

@@ -36,9 +36,9 @@
 #include <sound/seq_device.h>
 
 #if defined(CONFIG_SND_SEQ_DUMMY_MODULE)
-int seq_client_load[64] = {[0] = SNDRV_SEQ_CLIENT_DUMMY, [1 ... 63] = -1};
+int seq_client_load[15] = {[0] = SNDRV_SEQ_CLIENT_DUMMY, [1 ... 14] = -1};
 #else
-int seq_client_load[64] = {[0 ... 63] = -1};
+int seq_client_load[15] = {[0 ... 14] = -1};
 #endif
 int seq_default_timer_class = SNDRV_TIMER_CLASS_GLOBAL;
 int seq_default_timer_sclass = SNDRV_TIMER_SCLASS_NONE;

sound/core/seq/seq_clientmgr.c

@@ -47,9 +47,20 @@
  * 
  */
 
-/* range for dynamically allocated client numbers of kernel drivers */
-#define SNDRV_SEQ_DYNAMIC_CLIENT_BEGIN	16
-#define SNDRV_SEQ_DYNAMIC_CLIENT_END	48
+/*
+ * There are four ranges of client numbers (last two shared):
+ * 0..15: global clients
+ * 16..127: statically allocated client numbers for cards 0..27
+ * 128..191: dynamically allocated client numbers for cards 28..31
+ * 128..191: dynamically allocated client numbers for applications
+ */
+
+/* number of kernel non-card clients */
+#define SNDRV_SEQ_GLOBAL_CLIENTS	16
+/* clients per cards, for static clients */
+#define SNDRV_SEQ_CLIENTS_PER_CARD	4
+/* dynamically allocated client numbers (both kernel drivers and user space) */
+#define SNDRV_SEQ_DYNAMIC_CLIENTS_BEGIN	128
 
 #define SNDRV_SEQ_LFLG_INPUT	0x0001
 #define SNDRV_SEQ_LFLG_OUTPUT	0x0002
@@ -143,14 +154,14 @@ struct snd_seq_client *snd_seq_client_use_ptr(int clientid)
 	spin_unlock_irqrestore(&clients_lock, flags);
 #ifdef CONFIG_KMOD
 	if (!in_interrupt() && current->fs->root) {
-		static char client_requested[64];
+		static char client_requested[SNDRV_SEQ_GLOBAL_CLIENTS];
 		static char card_requested[SNDRV_CARDS];
-		if (clientid < 64) {
+		if (clientid < SNDRV_SEQ_GLOBAL_CLIENTS) {
 			int idx;
 			
 			if (! client_requested[clientid] && current->fs->root) {
 				client_requested[clientid] = 1;
-				for (idx = 0; idx < 64; idx++) {
+				for (idx = 0; idx < 15; idx++) {
 					if (seq_client_load[idx] < 0)
 						break;
 					if (seq_client_load[idx] == clientid) {
@@ -160,8 +171,9 @@ struct snd_seq_client *snd_seq_client_use_ptr(int clientid)
 					}
 				}
 			}
-		} else if (clientid >= 64 && clientid < 128) {
-			int card = (clientid - 64) / 4;
+		} else if (clientid < SNDRV_SEQ_DYNAMIC_CLIENTS_BEGIN) {
+			int card = (clientid - SNDRV_SEQ_GLOBAL_CLIENTS) /
+				SNDRV_SEQ_CLIENTS_PER_CARD;
 			if (card < snd_ecards_limit) {
 				if (! card_requested[card]) {
 					card_requested[card] = 1;
@@ -207,8 +219,7 @@ int __init client_init_data(void)
 }
 
 
-static struct snd_seq_client *seq_create_client1(int client_index, int poolsize,
-						 int kernel_client)
+static struct snd_seq_client *seq_create_client1(int client_index, int poolsize)
 {
 	unsigned long flags;
 	int c;
@@ -232,15 +243,9 @@ static struct snd_seq_client *seq_create_client1(int client_index, int poolsize,
 	/* find free slot in the client table */
 	spin_lock_irqsave(&clients_lock, flags);
 	if (client_index < 0) {
-		int cmin, cmax;
-		if (kernel_client) {
-			cmin = SNDRV_SEQ_DYNAMIC_CLIENT_BEGIN;
-			cmax = SNDRV_SEQ_DYNAMIC_CLIENT_END;
-		} else {
-			cmin = 128;
-			cmax = SNDRV_SEQ_MAX_CLIENTS;
-		}
-		for (c = cmin; c < cmax; c++) {
+		for (c = SNDRV_SEQ_DYNAMIC_CLIENTS_BEGIN;
+		     c < SNDRV_SEQ_MAX_CLIENTS;
+		     c++) {
 			if (clienttab[c] || clienttablock[c])
 				continue;
 			clienttab[client->number = c] = client;
@@ -319,7 +324,7 @@ static int snd_seq_open(struct inode *inode, struct file *file)
 
 	if (down_interruptible(&register_mutex))
 		return -ERESTARTSYS;
-	client = seq_create_client1(-1, SNDRV_SEQ_DEFAULT_EVENTS, 0);
+	client = seq_create_client1(-1, SNDRV_SEQ_DEFAULT_EVENTS);
 	if (client == NULL) {
 		up(&register_mutex);
 		return -ENOMEM;	/* failure code */
@@ -2220,23 +2225,23 @@ int snd_seq_create_kernel_client(struct snd_card *card, int client_index,
 
 	snd_assert(! in_interrupt(), return -EBUSY);
 
-	if (card && client_index > 3)
+	if (card && client_index >= SNDRV_SEQ_CLIENTS_PER_CARD)
 		return -EINVAL;
-	if (card == NULL && client_index > 63)
+	if (card == NULL && client_index >= SNDRV_SEQ_GLOBAL_CLIENTS)
 		return -EINVAL;
 
 	if (down_interruptible(&register_mutex))
 		return -ERESTARTSYS;
 
 	if (card) {
-		if (card->number < 16)
-			client_index += 64 + (card->number << 2);
-		else
+		client_index += SNDRV_SEQ_GLOBAL_CLIENTS
+			+ card->number * SNDRV_SEQ_CLIENTS_PER_CARD;
+		if (client_index >= SNDRV_SEQ_DYNAMIC_CLIENTS_BEGIN)
 			client_index = -1;
 	}
 
 	/* empty write queue as default */
-	client = seq_create_client1(client_index, 0, 1);
+	client = seq_create_client1(client_index, 0);
 	if (client == NULL) {
 		up(&register_mutex);
 		return -EBUSY;	/* failure code */