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kernel/linux-rt-4.4.41/sound/core/seq/seq_lock.c 1.5 KB
5113f6f70   김현기   kernel add
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  /*
   *  Do sleep inside a spin-lock
   *  Copyright (c) 1999 by Takashi Iwai <tiwai@suse.de>
   *
   *
   *   This program is free software; you can redistribute it and/or modify
   *   it under the terms of the GNU General Public License as published by
   *   the Free Software Foundation; either version 2 of the License, or
   *   (at your option) any later version.
   *
   *   This program is distributed in the hope that it will be useful,
   *   but WITHOUT ANY WARRANTY; without even the implied warranty of
   *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *   GNU General Public License for more details.
   *
   *   You should have received a copy of the GNU General Public License
   *   along with this program; if not, write to the Free Software
   *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
   *
   */
  
  #include <linux/export.h>
  #include <sound/core.h>
  #include "seq_lock.h"
  
  #if defined(CONFIG_SMP) || defined(CONFIG_SND_DEBUG)
  
  /* wait until all locks are released */
  void snd_use_lock_sync_helper(snd_use_lock_t *lockp, const char *file, int line)
  {
  	int max_count = 5 * HZ;
  
  	if (atomic_read(lockp) < 0) {
  		pr_warn("ALSA: seq_lock: lock trouble [counter = %d] in %s:%d
  ", atomic_read(lockp), file, line);
  		return;
  	}
  	while (atomic_read(lockp) > 0) {
  		if (max_count == 0) {
  			pr_warn("ALSA: seq_lock: timeout [%d left] in %s:%d
  ", atomic_read(lockp), file, line);
  			break;
  		}
  		schedule_timeout_uninterruptible(1);
  		max_count--;
  	}
  }
  
  EXPORT_SYMBOL(snd_use_lock_sync_helper);
  
  #endif