diff --git a/current.txt b/current.txt
index 34b3555..458e360 100644
--- a/current.txt
+++ b/current.txt
@@ -396,6 +396,7 @@
 d702fb01dc2a0733aa820b7eb65435ee3334f75632ef880bafd2fb8803a20a58 android.hardware.gnss@1.0::IGnssMeasurementCallback
 7c7721c0f773fcf422b71a4f558545e9e36acc973e58ca51e5bd53905cf46bc0 android.hardware.graphics.bufferqueue@1.0::IGraphicBufferProducer
 d4fea995378bb4f421b4e24ccf68cad2734ab07fe4f874a126ba558b99df5766 android.hardware.graphics.composer@2.1::IComposerClient
+f7d7cb747dc01a9fdb2d39a80003b4d8df9be733d65f5842198802eb6209db69 android.hardware.graphics.mapper@2.0::IMapper
 65a021fa89085b62fc96b2b6d3bef2f9103cf4d63379c68bc154fd9eef672852 android.hardware.health@1.0::types
 b7ecf29927055ec422ec44bf776223f07d79ad9f92ccf9becf167e62c2607e7a android.hardware.keymaster@4.0::IKeymasterDevice
 574e8f1499436fb4075894dcae0b36682427956ecb114f17f1fe22d116a83c6b android.hardware.neuralnetworks@1.0::IPreparedModel
diff --git a/graphics/mapper/2.0/IMapper.hal b/graphics/mapper/2.0/IMapper.hal
index 4566135..0e18f42 100644
--- a/graphics/mapper/2.0/IMapper.hal
+++ b/graphics/mapper/2.0/IMapper.hal
@@ -147,6 +147,9 @@
      * outside of accessRegion is undefined, except that it must not cause
      * process termination.
      *
+     * An accessRegion of all-zeros means the entire buffer. That is, it is
+     * equivalent to '(0,0)-(buffer width, buffer height)'.
+     *
      * data will be filled with a pointer to the locked buffer memory. This
      * address will represent the top-left corner of the entire buffer, even
      * if accessRegion does not begin at the top-left corner.