bianbu-linux-6.6/sound/core/seq/seq_lock.h
Ben Hutchings 8009d506a1 ALSA: seq: Enable 'use' locking in all configurations
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>
2017-10-18 08:01:46 +02:00

21 lines
573 B
C

#ifndef __SND_SEQ_LOCK_H
#define __SND_SEQ_LOCK_H
#include <linux/sched.h>
typedef atomic_t snd_use_lock_t;
/* initialize lock */
#define snd_use_lock_init(lockp) atomic_set(lockp, 0)
/* increment lock */
#define snd_use_lock_use(lockp) atomic_inc(lockp)
/* release lock */
#define snd_use_lock_free(lockp) atomic_dec(lockp)
/* wait until all locks are released */
void snd_use_lock_sync_helper(snd_use_lock_t *lock, const char *file, int line);
#define snd_use_lock_sync(lockp) snd_use_lock_sync_helper(lockp, __BASE_FILE__, __LINE__)
#endif /* __SND_SEQ_LOCK_H */