xref: /linux/sound/core/seq/seq_lock.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
1 /*
2  *  Do sleep inside a spin-lock
3  *  Copyright (c) 1999 by Takashi Iwai <tiwai@suse.de>
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 <sound/core.h>
23 #include "seq_lock.h"
24 
25 #if defined(CONFIG_SMP) || defined(CONFIG_SND_DEBUG)
26 
27 /* wait until all locks are released */
28 void snd_use_lock_sync_helper(snd_use_lock_t *lockp, const char *file, int line)
29 {
30 	int max_count = 5 * HZ;
31 
32 	if (atomic_read(lockp) < 0) {
33 		printk(KERN_WARNING "seq_lock: lock trouble [counter = %d] in %s:%d\n", atomic_read(lockp), file, line);
34 		return;
35 	}
36 	while (atomic_read(lockp) > 0) {
37 		if (max_count == 0) {
38 			snd_printk(KERN_WARNING "seq_lock: timeout [%d left] in %s:%d\n", atomic_read(lockp), file, line);
39 			break;
40 		}
41 		schedule_timeout_uninterruptible(1);
42 		max_count--;
43 	}
44 }
45 
46 EXPORT_SYMBOL(snd_use_lock_sync_helper);
47 
48 #endif
49