ALSA: Core - add snd_card_set_id() function

Introduce snd_card_set_id() function to allow lowlevel drivers to set
default identification name for card slot. The function checks also
for identification name collisions and tries to create unique name.

Also, the snd_card_create() function is simplified, because this new
function is used. As bonus, proper name collision checks are evaluated
at the card create time.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/include/sound/core.h b/include/sound/core.h
index 3dea798..0e8ae10 100644 (file)
--- a/include/sound/core.h
+++ b/include/sound/core.h
@@ -313,6 +313,7 @@ struct snd_card *snd_card_new(int idx, const char *id,
 int snd_card_disconnect(struct snd_card *card);
 int snd_card_free(struct snd_card *card);
 int snd_card_free_when_closed(struct snd_card *card);
+void snd_card_set_id(struct snd_card *card, const char *id);
 int snd_card_register(struct snd_card *card);
 int snd_card_info_init(void);
 int snd_card_info_done(void);

diff --git a/sound/core/init.c b/sound/core/init.c
index fd56afe..6557dd8 100644 (file)
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -152,15 +152,8 @@ int snd_card_create(int idx, const char *xid,
        card = kzalloc(sizeof(*card) + extra_size, GFP_KERNEL);
        if (!card)
                return -ENOMEM;
-       if (xid) {
-               if (!snd_info_check_reserved_words(xid)) {
-                       snd_printk(KERN_ERR
-                                  "given id string '%s' is reserved.\n", xid);
-                       err = -EBUSY;
-                       goto __error;
-               }
-               strlcpy(card->id, xid, sizeof(card->id));
-       }
+       if (xid)
+               snd_card_set_id(card, xid);
        err = 0;
        mutex_lock(&snd_card_mutex);
        if (idx < 0) {
@@ -483,22 +476,39 @@ int snd_card_free(struct snd_card *card)
 
 EXPORT_SYMBOL(snd_card_free);
 
-static void choose_default_id(struct snd_card *card)
+/**
+ *  snd_card_set_id - set card identification name
+ *  @card: soundcard structure
+ *  @nid: new identification string
+ *
+ *  This function sets the card identification and checks for name
+ *  collisions.
+ */
+void snd_card_set_id(struct snd_card *card, const char *nid)
 {
        int i, len, idx_flag = 0, loops = SNDRV_CARDS;
-       char *id, *spos;
+       const char *spos, *src;
+       char *id;
        
-       id = spos = card->shortname;    
-       while (*id != '\0') {
-               if (*id == ' ')
-                       spos = id + 1;
-               id++;
+       /* check if user specified own card->id */
+       if (card->id[0] != '\0')
+               return;
+       if (nid == NULL) {
+               id = card->shortname;
+               spos = src = id;
+               while (*id != '\0') {
+                       if (*id == ' ')
+                               spos = id + 1;
+                       id++;
+               }
+       } else {
+               spos = src = nid;
        }
        id = card->id;
        while (*spos != '\0' && !isalnum(*spos))
                spos++;
        if (isdigit(*spos))
-               *id++ = isalpha(card->shortname[0]) ? card->shortname[0] : 'D';
+               *id++ = isalpha(src[0]) ? src[0] : 'D';
        while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
                if (isalnum(*spos))
                        *id++ = *spos;
@@ -513,16 +523,20 @@ static void choose_default_id(struct snd_card *card)
 
        while (1) {
                if (loops-- == 0) {
-                       snd_printk(KERN_ERR "unable to choose default card id (%s)\n", id);
+                       snd_printk(KERN_ERR "unable to set card id (%s)\n", id);
                        strcpy(card->id, card->proc_root->name);
                        return;
                }
                if (!snd_info_check_reserved_words(id))
                        goto __change;
+               mutex_lock(&snd_card_mutex);
                for (i = 0; i < snd_ecards_limit; i++) {
-                       if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
+                       if (snd_cards[i] && !strcmp(snd_cards[i]->id, id)) {
+                               mutex_unlock(&snd_card_mutex);
                                goto __change;
+                       }
                }
+               mutex_unlock(&snd_card_mutex);
                break;
 
              __change:
@@ -539,14 +553,16 @@ static void choose_default_id(struct snd_card *card)
                        spos = id + len - 2;
                        if ((size_t)len <= sizeof(card->id) - 2)
                                spos++;
-                       *spos++ = '_';
-                       *spos++ = '1';
-                       *spos++ = '\0';
+                       *(char *)spos++ = '_';
+                       *(char *)spos++ = '1';
+                       *(char *)spos++ = '\0';
                        idx_flag++;
                }
        }
 }
 
+EXPORT_SYMBOL(snd_card_set_id);
+
 #ifndef CONFIG_SYSFS_DEPRECATED
 static ssize_t
 card_id_show_attr(struct device *dev,
@@ -641,7 +657,7 @@ int snd_card_register(struct snd_card *card)
                return 0;
        }
        if (card->id[0] == '\0')
-               choose_default_id(card);
+               snd_card_set_id(card, NULL);
        snd_cards[card->number] = card;
        mutex_unlock(&snd_card_mutex);
        init_info_for_card(card);