sound/core/seq/seq_lock.c

   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 <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                 pr_warn("ALSA: 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                         pr_warn("ALSA: seq_lock: timeout [%d left] in %s:%d\n", atomic_read(lockp), file, line);
  40                         break;
  41                 }
  42                 schedule_timeout_uninterruptible(1);
  43                 max_count--;
  44         }
  45 }
  46
  47 EXPORT_SYMBOL(snd_use_lock_sync_helper);
  48
  49 #endif