[ALSA] oxygen: use AC97 interrupt

After an AC97 register read or write, use the AC97 interrupt instead of
polling to wait for the access to be completed.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
diff --git a/sound/pci/oxygen/oxygen.h b/sound/pci/oxygen/oxygen.h
index 8fc9e7c..55ce244 100644
--- a/sound/pci/oxygen/oxygen.h
+++ b/sound/pci/oxygen/oxygen.h
@@ -3,6 +3,7 @@
 
 #include <linux/mutex.h>
 #include <linux/spinlock.h>
+#include <linux/wait.h>
 #include <linux/workqueue.h>
 #include "oxygen_regs.h"
 
@@ -65,6 +66,7 @@
 	struct snd_pcm_substream *streams[PCM_COUNT];
 	struct snd_kcontrol *controls[CONTROL_COUNT];
 	struct work_struct spdif_input_bits_work;
+	wait_queue_head_t ac97_waitqueue;
 };
 
 struct oxygen_model {