ALSA: Fix limit of 8 PCM devices in SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE

When compiled with CONFIG_SND_DYNAMIC_MINORS the ALSA core is fine to have more than 8 PCM devices per card, except one place - the SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE ioctl, which will not enumerate devices > 7. This patch fixes the issue, changing the devices list organisation. Instead of adding new device to the tail, the list is now kept always ordered (by card number, then device number). Thus, during enumeration, it is easy to discover the fact that there is no more given card's devices. Additionally the device field of struct snd_pcm had to be changed to int, as its "unsignednity" caused a lot of problems when comparing it to potentially negative signed values. (-1 is 0xffffffff or even more then ;-) Signed-off-by: Pawel Moll <pawel.moll@st.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jaroslav Kysela <perex@perex.cz>

ALSA: Fix limit of 8 PCM devices in SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE
When compiled with CONFIG_SND_DYNAMIC_MINORS the ALSA core is fine to have more than 8 PCM devices per card, except one place - the SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE ioctl, which will not enumerate devices > 7. This patch fixes the issue, changing the devices list organisation. Instead of adding new device to the tail, the list is now kept always ordered (by card number, then device number). Thus, during enumeration, it is easy to discover the fact that there is no more given card's devices. Additionally the device field of struct snd_pcm had to be changed to int, as its "unsignednity" caused a lot of problems when comparing it to potentially negative signed values. (-1 is 0xffffffff or even more then ;-) Signed-off-by: Pawel Moll <pawel.moll@st.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Pawel MOLL · Jaroslav Kysela
1 parent 030a07e441
Showing 4 changed files with 46 additions and 17 deletions Side-by-side Diff
include/sound/minors.h
include/sound/pcm.h
sound/core/pcm.c
sound/core/sound.c
@@ -21,6 +21,8 @@
  *
  */
  
+#define SNDRV_OS_MINORS			256
+
 #define SNDRV_MINOR_DEVICES		32
 #define SNDRV_MINOR_CARD(minor)		((minor) >> 5)
 #define SNDRV_MINOR_DEVICE(minor)	((minor) & 0x001f)
@@ -25,6 +25,7 @@
  
 #include <sound/asound.h>
 #include <sound/memalloc.h>
+#include <sound/minors.h>
 #include <linux/poll.h>
 #include <linux/mm.h>
 #include <linux/bitops.h>
@@ -84,7 +85,11 @@
  *
  */
  
-#define SNDRV_PCM_DEVICES		8
+#if defined(CONFIG_SND_DYNAMIC_MINORS)
+#define SNDRV_PCM_DEVICES	(SNDRV_OS_MINORS-2)
+#else
+#define SNDRV_PCM_DEVICES	8
+#endif
  
 #define SNDRV_PCM_IOCTL1_FALSE		((void *)0)
 #define SNDRV_PCM_IOCTL1_TRUE		((void *)1)
@@ -416,7 +421,7 @@
 struct snd_pcm {
 	struct snd_card *card;
 	struct list_head list;
-	unsigned int device;	/* device number */
+	int device; /* device number */
 	unsigned int info_flags;
 	unsigned short dev_class;
 	unsigned short dev_subclass;
@@ -42,7 +42,7 @@
 static int snd_pcm_dev_register(struct snd_device *device);
 static int snd_pcm_dev_disconnect(struct snd_device *device);
  
-static struct snd_pcm *snd_pcm_search(struct snd_card *card, int device)
+static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
 {
 	struct snd_pcm *pcm;
  
@@ -53,6 +53,37 @@
 	return NULL;
 }
  
+static int snd_pcm_next(struct snd_card *card, int device)
+{
+	struct snd_pcm *pcm;
+
+	list_for_each_entry(pcm, &snd_pcm_devices, list) {
+		if (pcm->card == card && pcm->device > device)
+			return pcm->device;
+		else if (pcm->card->number > card->number)
+			return -1;
+	}
+	return -1;
+}
+
+static int snd_pcm_add(struct snd_pcm *newpcm)
+{
+	struct snd_pcm *pcm;
+
+	list_for_each_entry(pcm, &snd_pcm_devices, list) {
+		if (pcm->card == newpcm->card && pcm->device == newpcm->device)
+			return -EBUSY;
+		if (pcm->card->number > newpcm->card->number ||
+				(pcm->card == newpcm->card &&
+				pcm->device > newpcm->device)) {
+			list_add(&newpcm->list, pcm->list.prev);
+			return 0;
+		}
+	}
+	list_add_tail(&newpcm->list, &snd_pcm_devices);
+	return 0;
+}
+
 static int snd_pcm_control_ioctl(struct snd_card *card,
 				 struct snd_ctl_file *control,
 				 unsigned int cmd, unsigned long arg)
@@ -65,14 +96,7 @@
 			if (get_user(device, (int __user *)arg))
 				return -EFAULT;
 			mutex_lock(&register_mutex);
-			device = device < 0 ? 0 : device + 1;
-			while (device < SNDRV_PCM_DEVICES) {
-				if (snd_pcm_search(card, device))
-					break;
-				device++;
-			}
-			if (device == SNDRV_PCM_DEVICES)
-				device = -1;
+			device = snd_pcm_next(card, device);
 			mutex_unlock(&register_mutex);
 			if (put_user(device, (int __user *)arg))
 				return -EFAULT;
@@ -98,7 +122,7 @@
 			if (get_user(subdevice, &info->subdevice))
 				return -EFAULT;
 			mutex_lock(&register_mutex);
-			pcm = snd_pcm_search(card, device);
+			pcm = snd_pcm_get(card, device);
 			if (pcm == NULL) {
 				err = -ENXIO;
 				goto _error;
  
  
@@ -931,11 +955,11 @@
  
 	snd_assert(pcm != NULL && device != NULL, return -ENXIO);
 	mutex_lock(&register_mutex);
-	if (snd_pcm_search(pcm->card, pcm->device)) {
+	err = snd_pcm_add(pcm);
+	if (err) {
 		mutex_unlock(&register_mutex);
-		return -EBUSY;
+		return err;
 	}
-	list_add_tail(&pcm->list, &snd_pcm_devices);
 	for (cidx = 0; cidx < 2; cidx++) {
 		int devtype = -1;
 		if (pcm->streams[cidx].substream == NULL)
@@ -34,8 +34,6 @@
 #include <linux/kmod.h>
 #include <linux/mutex.h>
  
-#define SNDRV_OS_MINORS 256
-
 static int major = CONFIG_SND_MAJOR;
 int snd_major;
 EXPORT_SYMBOL(snd_major);
...	...	@@ -21,6 +21,8 @@
21	21	*
22	22	*/
23	23
	24	+#define SNDRV_OS_MINORS 256
	25	+
24	26	#define SNDRV_MINOR_DEVICES 32
25	27	#define SNDRV_MINOR_CARD(minor) ((minor) >> 5)
26	28	#define SNDRV_MINOR_DEVICE(minor) ((minor) & 0x001f)
...	...	@@ -25,6 +25,7 @@
25	25
26	26	#include <sound/asound.h>
27	27	#include <sound/memalloc.h>
	28	+#include <sound/minors.h>
28	29	#include <linux/poll.h>
29	30	#include <linux/mm.h>
30	31	#include <linux/bitops.h>
...	...	@@ -84,7 +85,11 @@
84	85	*
85	86	*/
86	87
87		-#define SNDRV_PCM_DEVICES 8
	88	+#if defined(CONFIG_SND_DYNAMIC_MINORS)
	89	+#define SNDRV_PCM_DEVICES (SNDRV_OS_MINORS-2)
	90	+#else
	91	+#define SNDRV_PCM_DEVICES 8
	92	+#endif
88	93
89	94	#define SNDRV_PCM_IOCTL1_FALSE ((void *)0)
90	95	#define SNDRV_PCM_IOCTL1_TRUE ((void *)1)
...	...	@@ -416,7 +421,7 @@
416	421	struct snd_pcm {
417	422	struct snd_card *card;
418	423	struct list_head list;
419		- unsigned int device; /* device number */
	424	+ int device; /* device number */
420	425	unsigned int info_flags;
421	426	unsigned short dev_class;
422	427	unsigned short dev_subclass;
...	...	@@ -42,7 +42,7 @@
42	42	static int snd_pcm_dev_register(struct snd_device *device);
43	43	static int snd_pcm_dev_disconnect(struct snd_device *device);
44	44
45		-static struct snd_pcm snd_pcm_search(struct snd_card card, int device)
	45	+static struct snd_pcm snd_pcm_get(struct snd_card card, int device)
46	46	{
47	47	struct snd_pcm *pcm;
48	48
...	...	@@ -53,6 +53,37 @@
53	53	return NULL;
54	54	}
55	55
	56	+static int snd_pcm_next(struct snd_card *card, int device)
	57	+{
	58	+ struct snd_pcm *pcm;
	59	+
	60	+ list_for_each_entry(pcm, &snd_pcm_devices, list) {
	61	+ if (pcm->card == card && pcm->device > device)
	62	+ return pcm->device;
	63	+ else if (pcm->card->number > card->number)
	64	+ return -1;
	65	+ }
	66	+ return -1;
	67	+}
	68	+
	69	+static int snd_pcm_add(struct snd_pcm *newpcm)
	70	+{
	71	+ struct snd_pcm *pcm;
	72	+
	73	+ list_for_each_entry(pcm, &snd_pcm_devices, list) {
	74	+ if (pcm->card == newpcm->card && pcm->device == newpcm->device)
	75	+ return -EBUSY;
	76	+ if (pcm->card->number > newpcm->card->number \|\|
	77	+ (pcm->card == newpcm->card &&
	78	+ pcm->device > newpcm->device)) {
	79	+ list_add(&newpcm->list, pcm->list.prev);
	80	+ return 0;
	81	+ }
	82	+ }
	83	+ list_add_tail(&newpcm->list, &snd_pcm_devices);
	84	+ return 0;
	85	+}
	86	+
56	87	static int snd_pcm_control_ioctl(struct snd_card *card,
57	88	struct snd_ctl_file *control,
58	89	unsigned int cmd, unsigned long arg)
...	...	@@ -65,14 +96,7 @@
65	96	if (get_user(device, (int __user *)arg))
66	97	return -EFAULT;
67	98	mutex_lock(&register_mutex);
68		- device = device < 0 ? 0 : device + 1;
69		- while (device < SNDRV_PCM_DEVICES) {
70		- if (snd_pcm_search(card, device))
71		- break;
72		- device++;
73		- }
74		- if (device == SNDRV_PCM_DEVICES)
75		- device = -1;
	99	+ device = snd_pcm_next(card, device);
76	100	mutex_unlock(&register_mutex);
77	101	if (put_user(device, (int __user *)arg))
78	102	return -EFAULT;
...	...	@@ -98,7 +122,7 @@
98	122	if (get_user(subdevice, &info->subdevice))
99	123	return -EFAULT;
100	124	mutex_lock(&register_mutex);
101		- pcm = snd_pcm_search(card, device);
	125	+ pcm = snd_pcm_get(card, device);
102	126	if (pcm == NULL) {
103	127	err = -ENXIO;
104	128	goto _error;
105	129
106	130
...	...	@@ -931,11 +955,11 @@
931	955
932	956	snd_assert(pcm != NULL && device != NULL, return -ENXIO);
933	957	mutex_lock(&register_mutex);
934		- if (snd_pcm_search(pcm->card, pcm->device)) {
	958	+ err = snd_pcm_add(pcm);
	959	+ if (err) {
935	960	mutex_unlock(&register_mutex);
936		- return -EBUSY;
	961	+ return err;
937	962	}
938		- list_add_tail(&pcm->list, &snd_pcm_devices);
939	963	for (cidx = 0; cidx < 2; cidx++) {
940	964	int devtype = -1;
941	965	if (pcm->streams[cidx].substream == NULL)
...	...	@@ -34,8 +34,6 @@
34	34	#include <linux/kmod.h>
35	35	#include <linux/mutex.h>
36	36
37		-#define SNDRV_OS_MINORS 256
38		-
39	37	static int major = CONFIG_SND_MAJOR;
40	38	int snd_major;
41	39	EXPORT_SYMBOL(snd_major);