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[ALSA] Improve the slots option handling

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Fix and improve the slots option handling.  The sound core tries to
find the slot with the given module name first and assign if it's
still available.  If all pre-given slots are unavailable, then try
to find another free slot.

Also, when a module name begins with '!', it means the negative match:
the slot will be given for any modules but that one.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2008-05-27 17:59:24 +02:00
parent f9423e7a94
commit a93bbaa77e
2 changed files with 44 additions and 27 deletions
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4
Documentation/sound/alsa/ALSA-Configuration.txt
View File

@ -2271,6 +2271,10 @@ case above again, the first two slots are already reserved. If any
other driver (e.g. snd-usb-audio) is loaded before snd-interwave or
snd-ens1371, it will be assigned to the third or later slot.
When a module name is given with '!', the slot will be given for any
modules but that name. For example, "slots=!snd-pcsp" will reserve
the first slot for any modules but snd-pcsp.
ALSA PCM devices to OSS devices mapping
=======================================

67
sound/core/init.c
View File

@ -46,17 +46,24 @@ static char *slots[SNDRV_CARDS];
module_param_array(slots, charp, NULL, 0444);
MODULE_PARM_DESC(slots, "Module names assigned to the slots.");
/* return non-zero if the given index is already reserved for another
/* return non-zero if the given index is reserved for the given
* module via slots option
*/
static int module_slot_mismatch(struct module *module, int idx)
static int module_slot_match(struct module *module, int idx)
{
int match = 1;
#ifdef MODULE
char *s1, *s2;
const char *s1, *s2;
if (!module || !module->name || !slots[idx])
return 0;
s1 = slots[idx];
s2 = module->name;
s1 = module->name;
s2 = slots[idx];
if (*s2 == '!') {
match = 0; /* negative match */
s2++;
}
/* compare module name strings
* hyphens are handled as equivalent with underscore
*/
@ -68,12 +75,12 @@ static int module_slot_mismatch(struct module *module, int idx)
if (c2 == '-')
c2 = '_';
if (c1 != c2)
return 1;
return !match;
if (!c1)
break;
}
#endif
return 0;
#endif /* MODULE */
return match;
}
#if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
@ -129,7 +136,7 @@ struct snd_card *snd_card_new(int idx, const char *xid,
struct module *module, int extra_size)
{
struct snd_card *card;
int err;
int err, idx2;
if (extra_size < 0)
extra_size = 0;
@ -144,35 +151,41 @@ struct snd_card *snd_card_new(int idx, const char *xid,
err = 0;
mutex_lock(&snd_card_mutex);
if (idx < 0) {
int idx2;
for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
/* idx == -1 == 0xffff means: take any free slot */
if (~snd_cards_lock & idx & 1<<idx2) {
if (module_slot_mismatch(module, idx2))
continue;
idx = idx2;
if (idx >= snd_ecards_limit)
snd_ecards_limit = idx + 1;
break;
if (module_slot_match(module, idx2)) {
idx = idx2;
break;
}
}
} else {
if (idx < snd_ecards_limit) {
if (snd_cards_lock & (1 << idx))
err = -EBUSY; /* invalid */
} else {
if (idx < SNDRV_CARDS)
snd_ecards_limit = idx + 1; /* increase the limit */
else
err = -ENODEV;
}
}
if (idx < 0 || err < 0) {
if (idx < 0) {
for (idx2 = 0; idx2 < SNDRV_CARDS; idx2++)
/* idx == -1 == 0xffff means: take any free slot */
if (~snd_cards_lock & idx & 1<<idx2) {
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))
err = -EBUSY; /* invalid */
} else if (idx >= SNDRV_CARDS)
err = -ENODEV;
if (err < 0) {
mutex_unlock(&snd_card_mutex);
snd_printk(KERN_ERR "cannot find the slot for index %d (range 0-%i), error: %d\n",
idx, snd_ecards_limit - 1, err);
goto __error;
}
snd_cards_lock |= 1 << idx; /* lock it */
if (idx >= snd_ecards_limit)
snd_ecards_limit = idx + 1; /* increase the limit */
mutex_unlock(&snd_card_mutex);
card->number = idx;
card->module = module;