From: Takashi Iwai <tiwai@suse.de>
Date: Wed, 15 Oct 2014 12:00:16 +0000 (+0200)
Subject: ALSA: seq: Use atomic ops for autoload refcount
X-Git-Tag: v3.19-rc1~119^2~21^2~109^2~2
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=54841a06c54eb55918948c12ab9b5f02cacb6ab3;p=karo-tx-linux.git

ALSA: seq: Use atomic ops for autoload refcount

... just to robustify for races.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
---

diff --git a/sound/core/seq/seq_device.c b/sound/core/seq/seq_device.c
index 91a786a783e1..775ea9390110 100644
--- a/sound/core/seq/seq_device.c
+++ b/sound/core/seq/seq_device.c
@@ -127,15 +127,15 @@ static void snd_seq_device_info(struct snd_info_entry *entry,
 
 #ifdef CONFIG_MODULES
 /* avoid auto-loading during module_init() */
-static int snd_seq_in_init;
+static atomic_t snd_seq_in_init = ATOMIC_INIT(0);
 void snd_seq_autoload_lock(void)
 {
-	snd_seq_in_init++;
+	atomic_inc(&snd_seq_in_init);
 }
 
 void snd_seq_autoload_unlock(void)
 {
-	snd_seq_in_init--;
+	atomic_dec(&snd_seq_in_init);
 }
 #endif
 
@@ -147,7 +147,7 @@ void snd_seq_device_load_drivers(void)
 	/* Calling request_module during module_init()
 	 * may cause blocking.
 	 */
-	if (snd_seq_in_init)
+	if (atomic_read(&snd_seq_in_init))
 		return;
 
 	mutex_lock(&ops_mutex);