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ALSA: Refactor slot assignment code 

There are two loops that are almost identical but only with different
checks.  Refactor them with a simple helper, and give a bit more
comments what's doing there.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2014-01-23 11:02:15 +01:00
parent 4c3773eda4
commit deb6596f16
1 changed files with 30 additions and 27 deletions
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57
sound/core/init.c
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@ -131,6 +131,31 @@ static inline int init_info_for_card(struct snd_card *card)
#define init_info_for_card(card)
#endif
static int check_empty_slot(struct module *module, int slot)
{
return !slots[slot] || !*slots[slot];
}
/* return an empty slot number (>= 0) found in the given bitmask @mask.
* @mask == -1 == 0xffffffff means: take any free slot up to 32
* when no slot is available, return the original @mask as is.
*/
static int get_slot_from_bitmask(int mask, int (*check)(struct module *, int),
struct module *module)
{
int slot;
for (slot = 0; slot < SNDRV_CARDS; slot++) {
if (slot < 32 && !(mask & (1U << slot)))
continue;
if (!test_bit(slot, snd_cards_lock)) {
if (check(module, slot))
return slot; /* found */
}
}
return mask; /* unchanged */
}
/**
* snd_card_create - create and initialize a soundcard structure
* @idx: card index (address) [0 ... (SNDRV_CARDS-1)]
@ -152,7 +177,7 @@ int snd_card_create(int idx, const char *xid,
struct snd_card **card_ret)
{
struct snd_card *card;
int err, idx2;
int err;
if (snd_BUG_ON(!card_ret))
return -EINVAL;
@ -167,32 +192,10 @@ int snd_card_create(int idx, const char *xid,
strlcpy(card->id, xid, sizeof(card->id));
err = 0;
mutex_lock(&snd_card_mutex);
if (idx < 0) {
for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++) {
/* idx == -1 == 0xffff means: take any free slot */
if (idx2 < 32 && !(idx & (1U << idx2)))
continue;
if (!test_bit(idx2, snd_cards_lock)) {
if (module_slot_match(module, idx2)) {
idx = idx2;
break;
}
}
}
}
if (idx < 0) {
for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++) {
/* idx == -1 == 0xffff means: take any free slot */
if (idx2 < 32 && !(idx & (1U << idx2)))
continue;
if (!test_bit(idx2, snd_cards_lock)) {
if (!slots[idx2] || !*slots[idx2]) {
idx = idx2;
break;
}
}
}
}
if (idx < 0) /* first check the matching module-name slot */
idx = get_slot_from_bitmask(idx, module_slot_match, module);
if (idx < 0) /* if not matched, assign an empty slot */
idx = get_slot_from_bitmask(idx, check_empty_slot, module);
if (idx < 0)
err = -ENODEV;
else if (idx < snd_ecards_limit) {