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f4fa968950
The snd_cards[] array holds the card pointers that have been currently registered, and it's exported for the external modules that may need to refer a card object. But accessing to this array can be racy against the driver probe or removal, as the card registration or free may happen concurrently. This patch gets rid of the direct access to snd_cards[] array and provides a helper function to give the card object from the index number with a refcount management. Then the caller can access to the given card object safely, and releases it via snd_card_unref(). While we're at it, add a proper comment to snd_card_unref() and make it an inlined function for type-safety, too. Signed-off-by: Takashi Iwai <tiwai@suse.de>
45 lines
1.3 KiB
C
45 lines
1.3 KiB
C
/*
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* Advanced Linux Sound Architecture
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* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include <linux/init.h>
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#include <sound/core.h>
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static int __init alsa_sound_last_init(void)
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{
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struct snd_card *card;
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int idx, ok = 0;
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printk(KERN_INFO "ALSA device list:\n");
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for (idx = 0; idx < SNDRV_CARDS; idx++) {
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card = snd_card_ref(idx);
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if (card) {
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printk(KERN_INFO " #%i: %s\n", idx, card->longname);
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snd_card_unref(card);
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ok++;
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}
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}
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if (ok == 0)
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printk(KERN_INFO " No soundcards found.\n");
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return 0;
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}
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late_initcall_sync(alsa_sound_last_init);
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