diff --git a/Documentation/ABI/testing/configfs-usb-gadget-uac2 b/Documentation/ABI/testing/configfs-usb-gadget-uac2
index 244d96650123..9cddadc53e0b 100644
--- a/Documentation/ABI/testing/configfs-usb-gadget-uac2
+++ b/Documentation/ABI/testing/configfs-usb-gadget-uac2
@@ -30,4 +30,6 @@ Description:
 					(in 1/256 dB)
 		p_volume_res		playback volume control resolution
 					(in 1/256 dB)
+		req_number	the number of pre-allocated requests for both capture
+					and playback
 		=====================	=======================================