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. The same limit was present in OSS emulation code. It has
been fixed as well.

Additionally the device field of struct snd_pcm is now int, instead of
unsigned int, as there is no obvious reason for keeping it unsigned.
This caused a lot of problems with comparing this value with other
(almost always signed) variables. There is just one more place where
device number is unsigned - in struct snd_pcm_info, which should be
also sorted out in future.

Signed-off-by: Pawel MOLL <pawel.moll@st.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

diff --git a/include/sound/minors.h b/include/sound/minors.h
index 46bcd2023ed8e7d7e55f305d100168108414b8b4..a81798ab73edc1bcdeb8e39ff9068febd2647b51 100644 (file)
--- a/include/sound/minors.h
+++ b/include/sound/minors.h
@@ -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)

diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index 51d58ccda2d82d7158cbca22fb338bafa393c0e0..bfc096ac82e5a2a80aaed7c7eea34244ce5758c0 100644 (file)
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -84,8 +84,6 @@ struct snd_pcm_ops {
  *
  */
 
-#define SNDRV_PCM_DEVICES              8
-
 #define SNDRV_PCM_IOCTL1_FALSE         ((void *)0)
 #define SNDRV_PCM_IOCTL1_TRUE          ((void *)1)
 
@@ -416,7 +414,7 @@ struct snd_pcm_str {
 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;

diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c
index 4c601b192ddf3feb4117186d230a73f4538f1723..4ccd761a5f41161da1242a899818af42e7cb8fb7 100644 (file)
--- a/sound/core/oss/pcm_oss.c
+++ b/sound/core/oss/pcm_oss.c
@@ -2947,7 +2947,7 @@ static void register_oss_dsp(struct snd_pcm *pcm, int index)
 static int snd_pcm_oss_register_minor(struct snd_pcm *pcm)
 {
        pcm->oss.reg = 0;
-       if (dsp_map[pcm->card->number] == (int)pcm->device) {
+       if (dsp_map[pcm->card->number] == pcm->device) {
                char name[128];
                int duplex;
                register_oss_dsp(pcm, 0);
@@ -2963,7 +2963,7 @@ static int snd_pcm_oss_register_minor(struct snd_pcm *pcm)
                pcm->oss.reg++;
                pcm->oss.reg_mask |= 1;
        }
-       if (adsp_map[pcm->card->number] == (int)pcm->device) {
+       if (adsp_map[pcm->card->number] == pcm->device) {
                register_oss_dsp(pcm, 1);
                pcm->oss.reg++;
                pcm->oss.reg_mask |= 2;
@@ -2988,7 +2988,7 @@ static int snd_pcm_oss_disconnect_minor(struct snd_pcm *pcm)
                        snd_unregister_oss_device(SNDRV_OSS_DEVICE_TYPE_PCM,
                                                  pcm->card, 1);
                }
-               if (dsp_map[pcm->card->number] == (int)pcm->device) {
+               if (dsp_map[pcm->card->number] == pcm->device) {
 #ifdef SNDRV_OSS_INFO_DEV_AUDIO
                        snd_oss_info_unregister(SNDRV_OSS_INFO_DEV_AUDIO, pcm->card->number);
 #endif
@@ -3019,12 +3019,12 @@ static int __init alsa_pcm_oss_init(void)
 
        /* check device map table */
        for (i = 0; i < SNDRV_CARDS; i++) {
-               if (dsp_map[i] < 0 || dsp_map[i] >= SNDRV_PCM_DEVICES) {
+               if (dsp_map[i] < 0 || dsp_map[i] >= SNDRV_OS_MINORS) {
                        snd_printk(KERN_ERR "invalid dsp_map[%d] = %d\n",
                                   i, dsp_map[i]);
                        dsp_map[i] = 0;
                }
-               if (adsp_map[i] < 0 || adsp_map[i] >= SNDRV_PCM_DEVICES) {
+               if (adsp_map[i] < 0 || adsp_map[i] >= SNDRV_OS_MINORS) {
                        snd_printk(KERN_ERR "invalid adsp_map[%d] = %d\n",
                                   i, adsp_map[i]);
                        adsp_map[i] = 1;

diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index ece25c718e95e8f78c5a71b01df6e01e80519908..24271a3bd901846515a1470b6fa191df7e706dc4 100644 (file)
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -42,7 +42,7 @@ static int snd_pcm_dev_free(struct snd_device *device);
 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 inline struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
 {
        struct snd_pcm *pcm;
 
@@ -53,6 +53,37 @@ static struct snd_pcm *snd_pcm_search(struct snd_card *card, int device)
        return NULL;
 }
 
+static inline 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 inline 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 @@ static int snd_pcm_control_ioctl(struct snd_card *card,
                        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 @@ static int snd_pcm_control_ioctl(struct snd_card *card,
                        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 @@ static int snd_pcm_dev_register(struct snd_device *device)
 
        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)

diff --git a/sound/core/sound.c b/sound/core/sound.c
index 1003ae375d478429e128bb7138b751486f069178..838dd9ee957ce3e3549600cfca55e9400ee5b360 100644 (file)
--- a/sound/core/sound.c
+++ b/sound/core/sound.c
@@ -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);