diff --git a/Documentation/sound/alsa/ALSA-Configuration.txt b/Documentation/sound/alsa/ALSA-Configuration.txt
index 8975701..27126c4 100644
--- a/Documentation/sound/alsa/ALSA-Configuration.txt
+++ b/Documentation/sound/alsa/ALSA-Configuration.txt
@@ -886,6 +886,11 @@
 		disable)
     power_save_controller - Reset HD-audio controller in power-saving mode
 		(default = on)
+    align_buffer_size - Force rounding of buffer/period sizes to multiples
+    		      of 128 bytes. This is more efficient in terms of memory
+		      access but isn't required by the HDA spec and prevents
+		      users from specifying exact period/buffer sizes.
+		      (default = on)
 
     This module supports multiple cards and autoprobe.