diff --git a/services/inputflinger/InputReader.cpp b/services/inputflinger/InputReader.cpp
index 97565aa..72c4560 100644
--- a/services/inputflinger/InputReader.cpp
+++ b/services/inputflinger/InputReader.cpp
@@ -2897,7 +2897,7 @@
 // --- RotaryEncoderInputMapper ---
 
 RotaryEncoderInputMapper::RotaryEncoderInputMapper(InputDevice* device) :
-        InputMapper(device) {
+        InputMapper(device), mOrientation(DISPLAY_ORIENTATION_0) {
     mSource = AINPUT_SOURCE_ROTARY_ENCODER;
 }
 
@@ -2939,6 +2939,14 @@
     if (!changes) {
         mRotaryEncoderScrollAccumulator.configure(getDevice());
     }
+    if (!changes || (InputReaderConfiguration::CHANGE_DISPLAY_INFO)) {
+        DisplayViewport v;
+        if (config->getDisplayViewport(ViewportType::VIEWPORT_INTERNAL, NULL, &v)) {
+            mOrientation = v.orientation;
+        } else {
+            mOrientation = DISPLAY_ORIENTATION_0;
+        }
+    }
 }
 
 void RotaryEncoderInputMapper::reset(nsecs_t when) {
@@ -2976,6 +2984,10 @@
         policyFlags |= POLICY_FLAG_WAKE;
     }
 
+    if (mOrientation == DISPLAY_ORIENTATION_180) {
+        scroll = -scroll;
+    }
+
     // Send motion event.
     if (scrolled) {
         int32_t metaState = mContext->getGlobalMetaState();