mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2025-09-04 20:19:47 +08:00
8009d506a1
The 'use' locking macros are no-ops if neither SMP or SND_DEBUG is enabled. This might once have been OK in non-preemptible configurations, but even in that case snd_seq_read() may sleep while relying on a 'use' lock. So always use the proper implementations. Cc: stable@vger.kernel.org Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Takashi Iwai <tiwai@suse.de>
42 lines
1.4 KiB
C
42 lines
1.4 KiB
C
/*
|
|
* 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"
|
|
|
|
/* wait until all locks are released */
|
|
void snd_use_lock_sync_helper(snd_use_lock_t *lockp, const char *file, int line)
|
|
{
|
|
int warn_count = 5 * HZ;
|
|
|
|
if (atomic_read(lockp) < 0) {
|
|
pr_warn("ALSA: seq_lock: lock trouble [counter = %d] in %s:%d\n", atomic_read(lockp), file, line);
|
|
return;
|
|
}
|
|
while (atomic_read(lockp) > 0) {
|
|
if (warn_count-- == 0)
|
|
pr_warn("ALSA: seq_lock: waiting [%d left] in %s:%d\n", atomic_read(lockp), file, line);
|
|
schedule_timeout_uninterruptible(1);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(snd_use_lock_sync_helper);
|