ALSA: core - Refactor card id string creation code
The code to handle the card id string is fairly messy, so here is a
tidy up.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/core/init.c b/sound/core/init.c
index 3ac49b1..068cf08 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -480,74 +480,104 @@
EXPORT_SYMBOL(snd_card_free);
-static void snd_card_set_id_no_lock(struct snd_card *card, const char *nid)
+/* retrieve the last word of shortname or longname */
+static const char *retrieve_id_from_card_name(const char *name)
{
- int i, len, idx_flag = 0, loops = SNDRV_CARDS;
- const char *spos, *src;
+ const char *spos = name;
+
+ while (*name) {
+ if (isspace(*name) && isalnum(name[1]))
+ spos = name + 1;
+ name++;
+ }
+ return spos;
+}
+
+/* return true if the given id string doesn't conflict any other card ids */
+static bool card_id_ok(struct snd_card *card, const char *id)
+{
+ int i;
+ if (!snd_info_check_reserved_words(id))
+ return false;
+ for (i = 0; i < snd_ecards_limit; i++) {
+ if (snd_cards[i] && snd_cards[i] != card &&
+ !strcmp(snd_cards[i]->id, id))
+ return false;
+ }
+ return true;
+}
+
+/* copy to card->id only with valid letters from nid */
+static void copy_valid_id_string(struct snd_card *card, const char *src,
+ const char *nid)
+{
+ char *id = card->id;
+
+ while (*nid && !isalnum(*nid))
+ nid++;
+ if (isdigit(*nid))
+ *id++ = isalpha(*src) ? *src : 'D';
+ while (*nid && (size_t)(id - card->id) < sizeof(card->id) - 1) {
+ if (isalnum(*nid))
+ *id++ = *nid;
+ nid++;
+ }
+ *id = 0;
+}
+
+/* Set card->id from the given string
+ * If the string conflicts with other ids, add a suffix to make it unique.
+ */
+static void snd_card_set_id_no_lock(struct snd_card *card, const char *src,
+ const char *nid)
+{
+ int len, loops;
+ bool with_suffix;
+ bool is_default = false;
char *id;
- if (nid == NULL) {
- id = card->shortname;
- spos = src = id;
- while (*id != '\0') {
- if (*id == ' ')
- spos = id + 1;
- id++;
- }
- } else {
- spos = src = nid;
- }
+ copy_valid_id_string(card, src, nid);
id = card->id;
- while (*spos != '\0' && !isalnum(*spos))
- spos++;
- if (isdigit(*spos))
- *id++ = isalpha(src[0]) ? src[0] : 'D';
- while (*spos != '\0' && (size_t)(id - card->id) < sizeof(card->id) - 1) {
- if (isalnum(*spos))
- *id++ = *spos;
- spos++;
- }
- *id = '\0';
- id = card->id;
-
- if (*id == '\0')
+ again:
+ /* use "Default" for obviously invalid strings
+ * ("card" conflicts with proc directories)
+ */
+ if (!*id || !strncmp(id, "card", 4)) {
strcpy(id, "Default");
+ is_default = true;
+ }
- while (1) {
- if (loops-- == 0) {
- 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;
- for (i = 0; i < snd_ecards_limit; i++) {
- if (snd_cards[i] && !strcmp(snd_cards[i]->id, id))
- goto __change;
- }
- break;
+ with_suffix = false;
+ for (loops = 0; loops < SNDRV_CARDS; loops++) {
+ if (card_id_ok(card, id))
+ return; /* OK */
- __change:
len = strlen(id);
- if (idx_flag) {
- if (id[len-1] != '9')
- id[len-1]++;
- else
- id[len-1] = 'A';
- } else if ((size_t)len <= sizeof(card->id) - 3) {
- strcat(id, "_1");
- idx_flag++;
+ if (!with_suffix) {
+ /* add the "_X" suffix */
+ char *spos = id + len;
+ if (len > sizeof(card->id) - 3)
+ spos = id + sizeof(card->id) - 3;
+ strcpy(spos, "_1");
+ with_suffix = true;
} else {
- spos = id + len - 2;
- if ((size_t)len <= sizeof(card->id) - 2)
- spos++;
- *(char *)spos++ = '_';
- *(char *)spos++ = '1';
- *(char *)spos++ = '\0';
- idx_flag++;
+ /* modify the existing suffix */
+ if (id[len - 1] != '9')
+ id[len - 1]++;
+ else
+ id[len - 1] = 'A';
}
}
+ /* fallback to the default id */
+ if (!is_default) {
+ *id = 0;
+ goto again;
+ }
+ /* last resort... */
+ snd_printk(KERN_ERR "unable to set card id (%s)\n", id);
+ if (card->proc_root->name)
+ strcpy(card->id, card->proc_root->name);
}
/**
@@ -564,7 +594,7 @@
if (card->id[0] != '\0')
return;
mutex_lock(&snd_card_mutex);
- snd_card_set_id_no_lock(card, nid);
+ snd_card_set_id_no_lock(card, nid, nid);
mutex_unlock(&snd_card_mutex);
}
EXPORT_SYMBOL(snd_card_set_id);
@@ -596,22 +626,12 @@
memcpy(buf1, buf, copy);
buf1[copy] = '\0';
mutex_lock(&snd_card_mutex);
- if (!snd_info_check_reserved_words(buf1)) {
- __exist:
+ if (!card_id_ok(NULL, buf1)) {
mutex_unlock(&snd_card_mutex);
return -EEXIST;
}
- for (idx = 0; idx < snd_ecards_limit; idx++) {
- if (snd_cards[idx] && !strcmp(snd_cards[idx]->id, buf1)) {
- if (card == snd_cards[idx])
- goto __ok;
- else
- goto __exist;
- }
- }
strcpy(card->id, buf1);
snd_info_card_id_change(card);
-__ok:
mutex_unlock(&snd_card_mutex);
return count;
@@ -665,7 +685,18 @@
mutex_unlock(&snd_card_mutex);
return 0;
}
- snd_card_set_id_no_lock(card, card->id[0] == '\0' ? NULL : card->id);
+ if (*card->id) {
+ /* make a unique id name from the given string */
+ char tmpid[sizeof(card->id)];
+ memcpy(tmpid, card->id, sizeof(card->id));
+ snd_card_set_id_no_lock(card, tmpid, tmpid);
+ } else {
+ /* create an id from either shortname or longname */
+ const char *src;
+ src = *card->shortname ? card->shortname : card->longname;
+ snd_card_set_id_no_lock(card, src,
+ retrieve_id_from_card_name(src));
+ }
snd_cards[card->number] = card;
mutex_unlock(&snd_card_mutex);
init_info_for_card(card);