Linux Kernel  3.7.1
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seq_lock.c
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1 /*
2  * Do sleep inside a spin-lock
3  * Copyright (c) 1999 by Takashi Iwai <[email protected]>
4  *
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19  *
20  */
21 
22 #include <linux/export.h>
23 #include <sound/core.h>
24 #include "seq_lock.h"
25 
26 #if defined(CONFIG_SMP) || defined(CONFIG_SND_DEBUG)
27 
28 /* wait until all locks are released */
29 void snd_use_lock_sync_helper(snd_use_lock_t *lockp, const char *file, int line)
30 {
31  int max_count = 5 * HZ;
32 
33  if (atomic_read(lockp) < 0) {
34  printk(KERN_WARNING "seq_lock: lock trouble [counter = %d] in %s:%d\n", atomic_read(lockp), file, line);
35  return;
36  }
37  while (atomic_read(lockp) > 0) {
38  if (max_count == 0) {
39  snd_printk(KERN_WARNING "seq_lock: timeout [%d left] in %s:%d\n", atomic_read(lockp), file, line);
40  break;
41  }
43  max_count--;
44  }
45 }
46 
47 EXPORT_SYMBOL(snd_use_lock_sync_helper);
48 
49 #endif