[PATCH 1/7] ALSA: core: Use READ_ONCE() / WRITE_ONCE() for power state change

[Takashi Iwai]

We need proper barriers to handle the power state change of the card
from different CPUs.

Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 include/sound/core.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/sound/core.h b/include/sound/core.h
index 1f9aef0adbc9..d69dfc6c4953 100644
--- a/include/sound/core.h
+++ b/include/sound/core.h
@@ -142,12 +142,12 @@ struct snd_card {
 #ifdef CONFIG_PM
 static inline unsigned int snd_power_get_state(struct snd_card *card)
 {
-	return card->power_state;
+	return READ_ONCE(card->power_state);
 }
 
 static inline void snd_power_change_state(struct snd_card *card, unsigned int state)
 {
-	card->power_state = state;
+	WRITE_ONCE(card->power_state, state);
 	wake_up(&card->power_sleep);
 }
 
-- 
2.26.2