Add check for hexagon version between interface and skel.

libhexagon_interface and libhexagon_nn_skel should be used with matching versions. Users shouldn't use mixed versions as it will not work correctly.

PiperOrigin-RevId: 297239641
Change-Id: I4e82626fc395eaba23fd51f84fbb402e24b2fd8a

tensorflow/lite/experimental/delegates/hexagon/hexagon_delegate.cc

@@ -132,6 +132,30 @@ class HexagonDelegate : public TfLiteDelegate {
     if (hexagon_nn == nullptr) {
       return false;
     }
+    if (hexagon_nn->hexagon_nn_version != nullptr &&
+        hexagon_nn->hexagon_nn_hexagon_interface_version) {
+      int hexagon_nn_version = -1;
+      int hexagon_interface_version =
+          hexagon_nn->hexagon_nn_hexagon_interface_version();
+      if (hexagon_nn->hexagon_nn_version(&hexagon_nn_version) != 0) {
+        TFLITE_LOG_PROD(tflite::TFLITE_LOG_WARNING,
+                        "Failed to fetch Hexagon NN version. This might be "
+                        "because you're using incompatible versions of "
+                        "libhexagon_interface and libhexagon_nn_skel. "
+                        "You must use compatible versions. "
+                        "Refer to Tensorflow Lite Hexagon Delegate Guide.");
+        return false;
+      }
+      if (hexagon_nn_version != hexagon_interface_version) {
+        TFLITE_LOG_PROD(
+            tflite::TFLITE_LOG_WARNING,
+            "Incompatible versions between interface library and "
+            "libhexagon_skel %d vs %d. You must use compatible versions. "
+            "Refer to Tensorflow Lite Hexagon Delegate Guide.",
+            hexagon_interface_version, hexagon_nn_version);
+        return false;
+      }
+    }
     return hexagon_nn->hexagon_nn_is_device_supported &&
            hexagon_nn->hexagon_nn_is_device_supported();
   }

tensorflow/lite/experimental/delegates/hexagon/hexagon_implementation.cc

@@ -76,6 +76,8 @@ HexagonNN CreateNewHexagonInterface() {
   LOAD_FUNCTION(libhexagon_interface, hexagon_nn_is_device_supported,
                 hexagon_nn);
   LOAD_FUNCTION(libhexagon_interface, hexagon_nn_version, hexagon_nn);
+  LOAD_FUNCTION(libhexagon_interface, hexagon_nn_hexagon_interface_version,
+                hexagon_nn);
   hexagon_nn.interface_loaded = successfully_loaded;
   return hexagon_nn;
 }

tensorflow/lite/experimental/delegates/hexagon/hexagon_implementation.h

@@ -126,6 +126,9 @@ struct HexagonNN {
   // Otherwise.
   hexagon_nn_is_device_supported_fn* hexagon_nn_is_device_supported;
 
+  // Returns the version number of the interface library.
+  hexagon_nn_hexagon_interface_version_fn* hexagon_nn_hexagon_interface_version;
+
   hexagon_nn_version_fn* hexagon_nn_version = nullptr;
 
   bool interface_loaded = false;

tensorflow/lite/experimental/delegates/hexagon/hexagon_nn_interface.h

@@ -56,4 +56,7 @@ using hexagon_nn_is_device_supported_fn =
 
 using hexagon_nn_version_fn = decltype(hexagon_nn_version);
 
+using hexagon_nn_hexagon_interface_version_fn =
+    decltype(hexagon_nn_hexagon_interface_version);
+
 #endif  // TENSORFLOW_LITE_EXPERIMENTAL_DELEGATES_HEXAGON_HEXAGON_NN_INTERFACE_H_