From e7df2a3ae569ed6d178510f58b22308edac7a4c7 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Fri, 9 Mar 2012 17:41:53 +0100 Subject: 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 --- sound/core/init.c | 169 ++++++++++++++++++++++++++++++++---------------------- 1 file changed, 100 insertions(+), 69 deletions(-) (limited to 'sound/core/init.c') diff --git a/sound/core/init.c b/sound/core/init.c index 3ac49b1b7cb8..068cf08d3ffb 100644 --- a/sound/core/init.c +++ b/sound/core/init.c @@ -480,74 +480,104 @@ int snd_card_free(struct snd_card *card) 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; - char *id; - - if (nid == NULL) { - id = card->shortname; - spos = src = id; - while (*id != '\0') { - if (*id == ' ') - spos = id + 1; - id++; - } - } else { - spos = src = nid; + const char *spos = name; + + while (*name) { + if (isspace(*name) && isalnum(name[1])) + spos = name + 1; + name++; } - 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++; + 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; } - *id = '\0'; + return true; +} - id = card->id; +/* 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 (*id == '\0') + copy_valid_id_string(card, src, nid); + id = card->id; + + 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 @@ void snd_card_set_id(struct snd_card *card, const char *nid) 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 @@ card_id_store_attr(struct device *dev, struct device_attribute *attr, 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 @@ int snd_card_register(struct snd_card *card) 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); -- cgit v1.2.3