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authorTakashi Iwai <tiwai@suse.de>2013-05-15 10:46:39 +0400
committerTakashi Iwai <tiwai@suse.de>2013-05-24 18:41:46 +0400
commit7bb2491b35a254fe6fd592c32a142a2f2f31fe6e (patch)
treebe7933980d3449e54cad4395e3b53185324f29c3 /sound
parent8edbb198a62e2c3d0bea06ce50a4d45a009849b6 (diff)
downloadlinux-7bb2491b35a254fe6fd592c32a142a2f2f31fe6e.tar.xz
ALSA: Add kconfig to specify the max card numbers
Currently ALSA supports up to 32 card instances when the dynamic minor is used. While 32 cards are usually big enough for normal use cases, there are sometimes weird requirements with more card support. Actually, this limitation, 32, comes from the index option, where you can pass the bit mask to assign the card. Other than that, we can actually give more cards up to the minor number limits (currently 256, which can be extended more, too). This patch adds a new Kconfig to specify the max card numbers, and changes a few places to accept more than 32 cards. The only incompatibility with high card numbers would be the handling of index option. The index option can be still used to pass the bitmask for card assignments, but this works only up to 32 slots. More than 32, no bitmask style option is available but only a single slot can be specified via index option. Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound')
-rw-r--r--sound/core/Kconfig9
-rw-r--r--sound/core/init.c25
2 files changed, 25 insertions, 9 deletions
diff --git a/sound/core/Kconfig b/sound/core/Kconfig
index b413ed05e74d..c0c2f57a0d6f 100644
--- a/sound/core/Kconfig
+++ b/sound/core/Kconfig
@@ -157,6 +157,15 @@ config SND_DYNAMIC_MINORS
If you are unsure about this, say N here.
+config SND_MAX_CARDS
+ int "Max number of sound cards"
+ range 4 256
+ default 32
+ depends on SND_DYNAMIC_MINORS
+ help
+ Specify the max number of sound cards that can be assigned
+ on a single machine.
+
config SND_SUPPORT_OLD_API
bool "Support old ALSA API"
default y
diff --git a/sound/core/init.c b/sound/core/init.c
index ed4a4811b6a1..6b9087115da2 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -46,7 +46,8 @@ static LIST_HEAD(shutdown_files);
static const struct file_operations snd_shutdown_f_ops;
-static unsigned int snd_cards_lock; /* locked for registering/using */
+/* locked for registering/using */
+static DECLARE_BITMAP(snd_cards_lock, SNDRV_CARDS);
struct snd_card *snd_cards[SNDRV_CARDS];
EXPORT_SYMBOL(snd_cards);
@@ -167,29 +168,35 @@ int snd_card_create(int idx, const char *xid,
err = 0;
mutex_lock(&snd_card_mutex);
if (idx < 0) {
- for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
+ for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++) {
/* idx == -1 == 0xffff means: take any free slot */
- if (~snd_cards_lock & idx & 1<<idx2) {
+ if (idx2 < sizeof(int) && !(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++)
+ for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++) {
/* idx == -1 == 0xffff means: take any free slot */
- if (~snd_cards_lock & idx & 1<<idx2) {
+ if (idx2 < sizeof(int) && !(idx & (1U << idx2)))
+ continue;
+ if (!test_bit(idx2, snd_cards_lock)) {
if (!slots[idx2] || !*slots[idx2]) {
idx = idx2;
break;
}
}
+ }
}
if (idx < 0)
err = -ENODEV;
else if (idx < snd_ecards_limit) {
- if (snd_cards_lock & (1 << idx))
+ if (test_bit(idx, snd_cards_lock))
err = -EBUSY; /* invalid */
} else if (idx >= SNDRV_CARDS)
err = -ENODEV;
@@ -199,7 +206,7 @@ int snd_card_create(int idx, const char *xid,
idx, snd_ecards_limit - 1, err);
goto __error;
}
- snd_cards_lock |= 1 << idx; /* lock it */
+ set_bit(idx, snd_cards_lock); /* lock it */
if (idx >= snd_ecards_limit)
snd_ecards_limit = idx + 1; /* increase the limit */
mutex_unlock(&snd_card_mutex);
@@ -249,7 +256,7 @@ int snd_card_locked(int card)
int locked;
mutex_lock(&snd_card_mutex);
- locked = snd_cards_lock & (1 << card);
+ locked = test_bit(card, snd_cards_lock);
mutex_unlock(&snd_card_mutex);
return locked;
}
@@ -361,7 +368,7 @@ int snd_card_disconnect(struct snd_card *card)
/* phase 1: disable fops (user space) operations for ALSA API */
mutex_lock(&snd_card_mutex);
snd_cards[card->number] = NULL;
- snd_cards_lock &= ~(1 << card->number);
+ clear_bit(card->number, snd_cards_lock);
mutex_unlock(&snd_card_mutex);
/* phase 2: replace file->f_op with special dummy operations */