diff --git a/sound/usb/card.h b/sound/usb/card.h
index 23b6f23..6cc883c 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -107,6 +107,8 @@
 	int interface;	/* current interface */
 	int endpoint;	/* assigned endpoint */
 	struct audioformat *cur_audiofmt;	/* current audioformat pointer (for hw_params callback) */
+	snd_pcm_format_t pcm_format;	/* current audio format (for hw_params callback) */
+	unsigned int channels;		/* current number of channels (for hw_params callback) */
 	unsigned int cur_rate;		/* current rate (for hw_params callback) */
 	unsigned int period_bytes;	/* current period bytes (for hw_params callback) */
 	unsigned int altset_idx;     /* USB data format: index of alternate setting */