diff --git a/audio/common/all-versions/default/tests/hidlutils_tests.cpp b/audio/common/all-versions/default/tests/hidlutils_tests.cpp
index ec16b02..e5ed844 100644
--- a/audio/common/all-versions/default/tests/hidlutils_tests.cpp
+++ b/audio/common/all-versions/default/tests/hidlutils_tests.cpp
@@ -17,6 +17,7 @@
 #include <array>
 #include <string>
 
+#include <android-base/test_utils.h>
 #include <gtest/gtest.h>
 
 #define LOG_TAG "HidlUtils_Test"
@@ -1100,6 +1101,7 @@
 TYPED_TEST_SUITE(FilterTest, FilterTestTypeParams);
 
 TYPED_TEST(FilterTest, FilterOutNonVendorTags) {
+    SKIP_WITH_HWASAN; // b/230535046
     TypeParam emptyTags;
     EXPECT_EQ(emptyTags, HidlUtils::filterOutNonVendorTags(emptyTags));
 
diff --git a/audio/core/all-versions/vts/functional/7.0/AudioPrimaryHidlHalTest.cpp b/audio/core/all-versions/vts/functional/7.0/AudioPrimaryHidlHalTest.cpp
index f25c391..dfc2386 100644
--- a/audio/core/all-versions/vts/functional/7.0/AudioPrimaryHidlHalTest.cpp
+++ b/audio/core/all-versions/vts/functional/7.0/AudioPrimaryHidlHalTest.cpp
@@ -715,7 +715,7 @@
             sink.base.channelMask.value(getConfig().base.channelMask);
             sink.ext.mix({});
             sink.ext.mix().ioHandle = helper.getIoHandle();
-            sink.ext.mix().useCase.source(toString(xsd::AudioSource::AUDIO_SOURCE_MIC));
+            sink.ext.mix().useCase.source(initMetadata.tracks[0].source);
             EXPECT_OK(getDevice()->createAudioPatch(hidl_vec<AudioPortConfig>{source},
                                                     hidl_vec<AudioPortConfig>{sink},
                                                     returnIn(res, mPatchHandle)));
diff --git a/audio/core/all-versions/vts/functional/AudioPrimaryHidlHalTest.h b/audio/core/all-versions/vts/functional/AudioPrimaryHidlHalTest.h
index 38d6eff..38e9e5f 100644
--- a/audio/core/all-versions/vts/functional/AudioPrimaryHidlHalTest.h
+++ b/audio/core/all-versions/vts/functional/AudioPrimaryHidlHalTest.h
@@ -1239,23 +1239,30 @@
     : public OpenStreamTest<::android::hardware::audio::CORE_TYPES_CPP_VERSION::IStreamIn> {
     void SetUp() override {
         ASSERT_NO_FATAL_FAILURE(OpenStreamTest::SetUp());  // setup base
+        auto flags = getInputFlags();
 #if MAJOR_VERSION <= 6
         address.device = AudioDevice::IN_DEFAULT;
 #elif MAJOR_VERSION >= 7
         auto maybeSourceAddress = getCachedPolicyConfig().getSourceDeviceForMixPort(
                 getDeviceName(), getMixPortName());
+        auto& metadata = initMetadata.tracks[0];
         if (maybeSourceAddress.has_value() &&
             !xsd::isTelephonyDevice(maybeSourceAddress.value().deviceType)) {
             address = maybeSourceAddress.value();
-            auto& metadata = initMetadata.tracks[0];
             metadata.source = toString(xsd::AudioSource::AUDIO_SOURCE_UNPROCESSED);
             metadata.channelMask = getConfig().base.channelMask;
         } else {
             address.deviceType = toString(xsd::AudioDevice::AUDIO_DEVICE_IN_DEFAULT);
         }
-#endif
+#if MAJOR_VERSION == 7 && MINOR_VERSION >= 1
+        auto flagsIt = std::find(flags.begin(), flags.end(),
+                                 toString(xsd::AudioInOutFlag::AUDIO_INPUT_FLAG_ULTRASOUND));
+        if (flagsIt != flags.end()) {
+            metadata.source = toString(xsd::AudioSource::AUDIO_SOURCE_ULTRASOUND);
+        }
+#endif  // 7.1
+#endif  // MAJOR_VERSION >= 7
         const AudioConfig& config = getConfig();
-        auto flags = getInputFlags();
         testOpen(
                 [&](AudioIoHandle handle, AudioConfig config, auto cb) {
                     return getDevice()->openInputStream(handle, address, config, flags,
diff --git a/audio/effect/all-versions/default/Android.bp b/audio/effect/all-versions/default/Android.bp
index 1e01ffb..a3c3ed6 100644
--- a/audio/effect/all-versions/default/Android.bp
+++ b/audio/effect/all-versions/default/Android.bp
@@ -30,6 +30,7 @@
     ],
 
     shared_libs: [
+        "libaudioutils",
         "libbase",
         "libcutils",
         "libeffects",
@@ -48,6 +49,7 @@
         "libeffects_headers",
         "libhardware_headers",
         "libmedia_headers",
+        "libmediautils_headers",
     ],
 }
 
diff --git a/audio/effect/all-versions/default/Effect.cpp b/audio/effect/all-versions/default/Effect.cpp
index 49f6bf2..3baafc9 100644
--- a/audio/effect/all-versions/default/Effect.cpp
+++ b/audio/effect/all-versions/default/Effect.cpp
@@ -22,13 +22,11 @@
 #include "Effect.h"
 #include "common/all-versions/default/EffectMap.h"
 
-#include <memory.h>
-
 #define ATRACE_TAG ATRACE_TAG_AUDIO
-
 #include <HidlUtils.h>
 #include <android/log.h>
 #include <media/EffectsFactoryApi.h>
+#include <mediautils/ScopedStatistics.h>
 #include <util/EffectUtils.h>
 #include <utils/Trace.h>
 
@@ -49,21 +47,27 @@
 
 namespace {
 
+#define SCOPED_STATS()                                                       \
+    ::android::mediautils::ScopedStatistics scopedStatistics {               \
+        std::string("EffectHal::").append(__func__), mEffectHal->mStatistics \
+    }
+
 class ProcessThread : public Thread {
    public:
     // ProcessThread's lifespan never exceeds Effect's lifespan.
-    ProcessThread(std::atomic<bool>* stop, effect_handle_t effect,
-                  std::atomic<audio_buffer_t*>* inBuffer, std::atomic<audio_buffer_t*>* outBuffer,
-                  Effect::StatusMQ* statusMQ, EventFlag* efGroup)
-        : Thread(false /*canCallJava*/),
-          mStop(stop),
-          mEffect(effect),
-          mHasProcessReverse((*mEffect)->process_reverse != NULL),
-          mInBuffer(inBuffer),
-          mOutBuffer(outBuffer),
-          mStatusMQ(statusMQ),
-          mEfGroup(efGroup) {}
-    virtual ~ProcessThread() {}
+     ProcessThread(std::atomic<bool>* stop, effect_handle_t effect,
+                   std::atomic<audio_buffer_t*>* inBuffer, std::atomic<audio_buffer_t*>* outBuffer,
+                   Effect::StatusMQ* statusMQ, EventFlag* efGroup, Effect* effectHal)
+         : Thread(false /*canCallJava*/),
+           mStop(stop),
+           mEffect(effect),
+           mHasProcessReverse((*mEffect)->process_reverse != NULL),
+           mInBuffer(inBuffer),
+           mOutBuffer(outBuffer),
+           mStatusMQ(statusMQ),
+           mEfGroup(efGroup),
+           mEffectHal(effectHal) {}
+     virtual ~ProcessThread() {}
 
    private:
     std::atomic<bool>* mStop;
@@ -73,6 +77,7 @@
     std::atomic<audio_buffer_t*>* mOutBuffer;
     Effect::StatusMQ* mStatusMQ;
     EventFlag* mEfGroup;
+    Effect* const mEffectHal;
 
     bool threadLoop() override;
 };
@@ -102,6 +107,9 @@
             audio_buffer_t* outBuffer =
                 std::atomic_load_explicit(mOutBuffer, std::memory_order_relaxed);
             if (inBuffer != nullptr && outBuffer != nullptr) {
+                // Time this effect process
+                SCOPED_STATS();
+
                 if (efState & static_cast<uint32_t>(MessageQueueFlagBits::REQUEST_PROCESS)) {
                     processResult = (*mEffect)->process(mEffect, inBuffer, outBuffer);
                 } else {
@@ -359,7 +367,7 @@
 
     // Create and launch the thread.
     mProcessThread = new ProcessThread(&mStopProcessThread, mHandle, &mHalInBufferPtr,
-                                       &mHalOutBufferPtr, tempStatusMQ.get(), mEfGroup);
+                                       &mHalOutBufferPtr, tempStatusMQ.get(), mEfGroup, this);
     status = mProcessThread->run("effect", PRIORITY_URGENT_AUDIO);
     if (status != OK) {
         ALOGW("failed to start effect processing thread: %s", strerror(-status));
@@ -749,6 +757,8 @@
     if (fd.getNativeHandle() != nullptr && fd->numFds == 1) {
         uint32_t cmdData = fd->data[0];
         (void)sendCommand(EFFECT_CMD_DUMP, "DUMP", sizeof(cmdData), &cmdData);
+        const std::string s = mStatistics->dump();
+        if (s.size() != 0) write(cmdData, s.c_str(), s.size());
     }
     return Void();
 }
diff --git a/audio/effect/all-versions/default/Effect.h b/audio/effect/all-versions/default/Effect.h
index f9a6796..011544d 100644
--- a/audio/effect/all-versions/default/Effect.h
+++ b/audio/effect/all-versions/default/Effect.h
@@ -29,6 +29,7 @@
 #include <fmq/MessageQueue.h>
 #include <hidl/MQDescriptor.h>
 #include <hidl/Status.h>
+#include <mediautils/MethodStatistics.h>
 #include <utils/Thread.h>
 
 #include <hardware/audio_effect.h>
@@ -169,7 +170,11 @@
     Result setParameterImpl(uint32_t paramSize, const void* paramData, uint32_t valueSize,
                             const void* valueData);
 
-   private:
+    // process execution statistics
+    const std::shared_ptr<mediautils::MethodStatistics<std::string>> mStatistics =
+            std::make_shared<mediautils::MethodStatistics<std::string>>();
+
+  private:
     friend struct VirtualizerEffect;  // for getParameterImpl
     friend struct VisualizerEffect;   // to allow executing commands
 
diff --git a/bluetooth/1.0/default/test/fuzzer/bluetoothV1.0_fuzzer.cpp b/bluetooth/1.0/default/test/fuzzer/bluetoothV1.0_fuzzer.cpp
index 90cdc66..fb8df99 100644
--- a/bluetooth/1.0/default/test/fuzzer/bluetoothV1.0_fuzzer.cpp
+++ b/bluetooth/1.0/default/test/fuzzer/bluetoothV1.0_fuzzer.cpp
@@ -88,11 +88,18 @@
     }
     mBtHci->close();
     mBtHci.clear();
+    for (size_t i = 0; i < mFdCount; ++i) {
+      if (mFdList[i]) {
+        close(mFdList[i]);
+      }
+    }
   }
   bool init(const uint8_t* data, size_t size);
   void process();
 
  private:
+  size_t mFdCount = 1;
+  int32_t mFdList[CH_MAX] = {0};
   sp<BluetoothHci> mBtHci = nullptr;
   FuzzedDataProvider* mFdp = nullptr;
 };
@@ -143,17 +150,15 @@
   bool shouldSetH4Protocol = mFdp->ConsumeBool();
   BtVendor* btVendor = BtVendor::getInstance();
 
-  size_t fdcount = 1;
-  int32_t fdList[CH_MAX] = {0};
   if (!shouldSetH4Protocol) {
-    fdcount = mFdp->ConsumeIntegralInRange<size_t>(kMinFdcount, CH_MAX - 1);
+    mFdCount = mFdp->ConsumeIntegralInRange<size_t>(kMinFdcount, CH_MAX - 1);
   }
 
-  for (size_t i = 0; i < fdcount; ++i) {
-    fdList[i] = open("/dev/null", O_RDWR | O_CREAT);
+  for (size_t i = 0; i < mFdCount; ++i) {
+    mFdList[i] = open("/dev/null", O_RDWR | O_CREAT);
   }
 
-  btVendor->populateFdList(fdList, fdcount);
+  btVendor->populateFdList(mFdList, mFdCount);
   mBtHci->initialize(bluetoothCallback);
 
   if (!bluetoothCallback->isInitialized) {
@@ -181,12 +186,6 @@
   }
 
   btVendor->callRemainingCbacks();
-
-  for (size_t i = 0; i < fdcount; ++i) {
-    if (fdList[i]) {
-      close(fdList[i]);
-    }
-  }
 }
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
diff --git a/compatibility_matrices/Android.bp b/compatibility_matrices/Android.bp
index 422b37e..524242f 100644
--- a/compatibility_matrices/Android.bp
+++ b/compatibility_matrices/Android.bp
@@ -87,7 +87,6 @@
 
 vintf_compatibility_matrix {
     name: "framework_compatibility_matrix.current.xml",
-    enabled: false,
     stem: "compatibility_matrix.current.xml",
     srcs: [
         "compatibility_matrix.current.xml",
diff --git a/compatibility_matrices/Android.mk b/compatibility_matrices/Android.mk
index d6a44d0..d19f0da 100644
--- a/compatibility_matrices/Android.mk
+++ b/compatibility_matrices/Android.mk
@@ -103,6 +103,7 @@
     framework_compatibility_matrix.5.xml \
     framework_compatibility_matrix.6.xml \
     framework_compatibility_matrix.7.xml \
+    framework_compatibility_matrix.current.xml \
     framework_compatibility_matrix.device.xml \
 
 my_framework_matrix_deps += \
diff --git a/security/keymint/aidl/android/hardware/security/keymint/ProtectedData.aidl b/security/keymint/aidl/android/hardware/security/keymint/ProtectedData.aidl
index cfbf171..6db58f2 100644
--- a/security/keymint/aidl/android/hardware/security/keymint/ProtectedData.aidl
+++ b/security/keymint/aidl/android/hardware/security/keymint/ProtectedData.aidl
@@ -18,13 +18,20 @@
 
 /**
  * ProtectedData contains the encrypted BCC and the ephemeral MAC key used to
- * authenticate the keysToSign (see keysToSignMac output argument).
+ * authenticate the keysToSign (see keysToSignMac output argument of
+ * IRemotelyProvisionedComponent.generateCertificateRequest).
  * @hide
  */
 @VintfStability
 parcelable ProtectedData {
     /**
-     * ProtectedData is a COSE_Encrypt structure, specified by the following CDDL
+     * ProtectedData is a COSE_Encrypt structure, encrypted with an AES key that is agreed upon
+     * using Elliptic-curve Diffie-Hellman. The contents of the structure are specified by the
+     * following CDDL [RFC8610].
+     *
+     * Notes:
+     *   - None of the CBOR in ProtectedData uses CBOR tags. If an implementation includes
+     *     tags, parsers may reject the data.
      *
      *     ProtectedData = [               // COSE_Encrypt
      *         protected: bstr .cbor {
@@ -34,13 +41,18 @@
      *             5 : bstr .size 12       // IV
      *         },
      *         ciphertext: bstr,           // AES-GCM-256(K, .cbor ProtectedDataPayload)
+     *                                     // Where the encryption key 'K' is derived as follows:
+     *                                     // ikm = ECDH(EEK_pub, Ephemeral_priv)
+     *                                     // salt = null
+     *                                     // info = .cbor Context (see below)
+     *                                     // K = HKDF-SHA-256(ikm, salt, info)
      *         recipients : [
      *             [                       // COSE_Recipient
      *                 protected : bstr .cbor {
      *                     1 : -25         // Algorithm : ECDH-ES + HKDF-256
      *                 },
      *                 unprotected : {
-     *                     -1 : PubKeyX25519 / PubKeyEcdhP256  // Of the sender
+     *                     -1 : PubKeyX25519 / PubKeyEcdhP256  // Ephemeral_pub
      *                     4 : bstr,       // KID : EEK ID
      *                 },
      *                 ciphertext : nil
@@ -48,14 +60,14 @@
      *         ]
      *     ]
      *
-     *     K = HKDF-256(ECDH(EEK_pub, Ephemeral_priv), Context)
-     *
-     *     Context = [                     // COSE_KDF_Context
+     *     // The COSE_KDF_Context that is used to derive the ProtectedData encryption key with
+     *     // HKDF. See details on use in ProtectedData comments above.
+     *     Context = [
      *         AlgorithmID : 3             // AES-GCM 256
      *         PartyUInfo : [
      *             identity : bstr "client"
      *             nonce : bstr .size 0,
-     *             other : bstr            // Ephemeral pubkey
+     *             other : bstr            // Ephemeral_pub
      *         ],
      *         PartyVInfo : [
      *             identity : bstr "server",
@@ -68,41 +80,55 @@
      *         ]
      *     ]
      *
+     *     // The data that is encrypted and included in ProtectedData ciphertext (see above).
      *     ProtectedDataPayload [
      *         SignedMac,
      *         Bcc,
      *         ? AdditionalDKSignatures,
      *     ]
+     *
+     *     // AdditionalDKSignatures allows the platform to provide additional certifications
+     *     // for the DK_pub. For example, this could be provided by the hardware vendor, who
+     *     // certifies all of their devices. The SignerName is a free-form string describing
+     *     // who generated the signature.
      *     AdditionalDKSignatures = {
      *         + SignerName => DKCertChain
      *     }
      *
+     *     // SignerName is a string identifier that indicates both the signing authority as
+     *     // well as the format of the DKCertChain
      *     SignerName = tstr
      *
      *     DKCertChain = [
-     *         2* Certificate                      // Root -> Leaf.  Root is the vendor
-     *                                             // self-signed cert, leaf contains DK_pub
+     *         2* Certificate           // Root -> ... -> Leaf. "Root" is the vendor self-signed
+     *                                  // cert, "Leaf" contains DK_pub. There may also be
+     *                                  // intermediate certificates between Root and Leaf.
      *     ]
      *
-     *     Certificate = COSE_Sign1 of a public key
+     *     // Certificates may be either:
+     *     // 1. COSE_Sign1, with payload containing PubKeyEd25519 or PubKeyECDSA256
+     *     // 2. a bstr containing a DER-encoded X.509 certificate (RSA, NIST P-curve, or edDSA)
+     *     Certificate = COSE_Sign1 / bstr
      *
-     *     SignedMac = [                                  // COSE_Sign1
-     *         bstr .cbor {                               // Protected params
-     *             1 : AlgorithmEdDSA / AlgorithmES256,   // Algorithm
+     *     // The SignedMac, which authenticates the MAC key that is used to authenticate the
+     *     // keysToSign.
+     *     SignedMac = [                                // COSE_Sign1
+     *         bstr .cbor {                             // Protected params
+     *             1 : AlgorithmEdDSA / AlgorithmES256, // Algorithm
      *         },
-     *         {},                   // Unprotected params
-     *         bstr .size 32,                  // MAC key
+     *         {},                                      // Unprotected params
+     *         bstr .size 32,                           // Payload: MAC key
      *         bstr // PureEd25519(KM_priv, bstr .cbor SignedMac_structure) /
      *              // ECDSA(KM_priv, bstr .cbor SignedMac_structure)
      *     ]
      *
-     *     SignedMac_structure = [
+     *     SignedMac_structure = [                      //  COSE Sig_structure
      *         "Signature1",
-     *         bstr .cbor {                               // Protected params
-     *             1 : AlgorithmEdDSA / AlgorithmES256,   // Algorithm
+     *         bstr .cbor {                             // Protected params
+     *             1 : AlgorithmEdDSA / AlgorithmES256, // Algorithm
      *         },
-     *         bstr .cbor SignedMacAad
-     *         bstr .size 32                              // MAC key
+     *         bstr .cbor SignedMacAad,
+     *         bstr .size 32                            // MAC key
      *     ]
      *
      *     SignedMacAad = [
@@ -114,31 +140,48 @@
      *                                   // the signature.
      *     ]
      *
+     *     VerifiedDeviceInfo = DeviceInfo  // See DeviceInfo.aidl
+     *
+     *     // The BCC is the boot certificate chain, containing measurements about the device
+     *     // boot chain. The BCC generally follows the Open Profile for DICE specification at
+     *     // https://pigweed.googlesource.com/open-dice/+/HEAD/docs/specification.md.
+     *     //
+     *     // The first entry in the Bcc is the DK_pub, encoded as a COSE_key. All entries after
+     *     // the first describe a link in the boot chain (e.g. bootloaders: BL1, BL2, ... BLN).
+     *     // Note that there is no BccEntry for DK_pub, only a "bare" COSE_key.
      *     Bcc = [
      *         PubKeyEd25519 / PubKeyECDSA256, // DK_pub
      *         + BccEntry,                     // Root -> leaf (KM_pub)
      *     ]
      *
-     *     BccPayload = {                     // CWT
-     *         1 : tstr,                      // Issuer
-     *         2 : tstr,                      // Subject
-     *         // See the Open Profile for DICE for details on these fields.
-     *         ? -4670545 : bstr,             // Code Hash
-     *         ? -4670546 : bstr,             // Code Descriptor
-     *         ? -4670547 : bstr,             // Configuration Hash
-     *         ? -4670548 : bstr .cbor {      // Configuration Descriptor
-     *             ? -70002 : tstr,           // Component name
-     *             ? -70003 : int,            // Firmware version
-     *             ? -70004 : null,           // Resettable
-     *         },
-     *         ? -4670549 : bstr,             // Authority Hash
-     *         ? -4670550 : bstr,             // Authority Descriptor
-     *         ? -4670551 : bstr,             // Mode
+     *     // This is the signed payload for each entry in the Bcc. Note that the "Configuration
+     *     // Input Values" described by the Open Profile are not used here. Instead, the Bcc
+     *     // defines its own configuration values for the Configuration Descriptor field. See
+     *     // the Open Profile for DICE for more details on the fields. All hashes are SHA256.
+     *     BccPayload = {                               // CWT [RFC8392]
+     *         1 : tstr,                                // Issuer
+     *         2 : tstr,                                // Subject
      *         -4670552 : bstr .cbor PubKeyEd25519 /
-     *                    bstr .cbor PubKeyECDSA256   // Subject Public Key
-     *         -4670553 : bstr                // Key Usage
+     *                    bstr .cbor PubKeyECDSA256,    // Subject Public Key
+     *         -4670553 : bstr                          // Key Usage
+     *
+     *         // NOTE: All of the following fields may be omitted for a "Degenerate BCC", as
+     *         //       described by IRemotelyProvisionedComponent.aidl.
+     *         -4670545 : bstr,                         // Code Hash
+     *         ? -4670546 : bstr,                       // Code Descriptor
+     *         ? -4670547 : bstr,                       // Configuration Hash
+     *         -4670548 : bstr .cbor {                  // Configuration Descriptor
+     *             ? -70002 : tstr,                         // Component name
+     *             ? -70003 : int,                          // Firmware version
+     *             ? -70004 : null,                         // Resettable
+     *         },
+     *         -4670549 : bstr,                         // Authority Hash
+     *         ? -4670550 : bstr,                       // Authority Descriptor
+     *         -4670551 : bstr,                         // Mode
      *     }
      *
+     *     // Each entry in the Bcc is a BccPayload signed by the key from the previous entry
+     *     // in the Bcc array.
      *     BccEntry = [                                  // COSE_Sign1 (untagged)
      *         protected : bstr .cbor {
      *             1 : AlgorithmEdDSA / AlgorithmES256,  // Algorithm
@@ -159,8 +202,8 @@
      *         payload: bstr .cbor BccPayload
      *     ]
      *
-     *     VerifiedDeviceInfo = DeviceInfo  // See DeviceInfo.aidl
-     *
+     *     // The following section defines some types that are reused throughout the above
+     *     // data structures.
      *     PubKeyX25519 = {                 // COSE_Key
      *          1 : 1,                      // Key type : Octet Key Pair
      *         -1 : 4,                      // Curve : X25519
@@ -168,25 +211,25 @@
      *     }
      *
      *     PubKeyEd25519 = {                // COSE_Key
-     *         1 : 1,                         // Key type : octet key pair
-     *         3 : AlgorithmEdDSA,            // Algorithm : EdDSA
-     *         -1 : 6,                        // Curve : Ed25519
-     *         -2 : bstr                      // X coordinate, little-endian
+     *         1 : 1,                       // Key type : octet key pair
+     *         3 : AlgorithmEdDSA,          // Algorithm : EdDSA
+     *         -1 : 6,                      // Curve : Ed25519
+     *         -2 : bstr                    // X coordinate, little-endian
      *     }
      *
-     *     PubKeyEcdhP256 = {              // COSE_Key
-     *          1 : 2,      // Key type : EC2
-     *          -1 : 1,     // Curve : P256
-     *          -2 : bstr   // Sender X coordinate
-     *          -3 : bstr   // Sender Y coordinate
+     *     PubKeyEcdhP256 = {               // COSE_Key
+     *          1 : 2,                      // Key type : EC2
+     *          -1 : 1,                     // Curve : P256
+     *          -2 : bstr                   // Sender X coordinate
+     *          -3 : bstr                   // Sender Y coordinate
      *     }
      *
-     *     PubKeyECDSA256 = {                 // COSE_Key
-     *         1 : 2,                         // Key type : EC2
-     *         3 : AlgorithmES256,            // Algorithm : ECDSA w/ SHA-256
-     *         -1 : 1,                        // Curve: P256
-     *         -2 : bstr,                     // X coordinate
-     *         -3 : bstr                      // Y coordinate
+     *     PubKeyECDSA256 = {               // COSE_Key
+     *         1 : 2,                       // Key type : EC2
+     *         3 : AlgorithmES256,          // Algorithm : ECDSA w/ SHA-256
+     *         -1 : 1,                      // Curve: P256
+     *         -2 : bstr,                   // X coordinate
+     *         -3 : bstr                    // Y coordinate
      *     }
      *
      *     AlgorithmES256 = -7
diff --git a/security/keymint/aidl/android/hardware/security/keymint/Tag.aidl b/security/keymint/aidl/android/hardware/security/keymint/Tag.aidl
index b28ebcb..42dfad5 100644
--- a/security/keymint/aidl/android/hardware/security/keymint/Tag.aidl
+++ b/security/keymint/aidl/android/hardware/security/keymint/Tag.aidl
@@ -504,7 +504,9 @@
      * that is necessary during all uses of the key.  In particular, calls to exportKey() and
      * getKeyCharacteristics() must provide the same value to the clientId parameter, and calls to
      * begin() must provide this tag and the same associated data as part of the inParams set.  If
-     * the correct data is not provided, the method must return ErrorCode::INVALID_KEY_BLOB.
+     * the correct data is not provided, the method must return ErrorCode::INVALID_KEY_BLOB.  Note
+     * that a key with a zero-length APPLICATION_ID cannot have its key characteristics retrieved
+     * using getKeyCharacteristics() due to a historical limitation of the API.
      *
      * The content of this tag must be bound to the key cryptographically, meaning it must not be
      * possible for an adversary who has access to all of the secure world secrets but does not have
@@ -525,7 +527,9 @@
      * that is necessary during all uses of the key.  In particular, calls to begin() and
      * exportKey() must provide the same value to the appData parameter, and calls to begin must
      * provide this tag and the same associated data as part of the inParams set.  If the correct
-     * data is not provided, the method must return ErrorCode::INVALID_KEY_BLOB.
+     * data is not provided, the method must return ErrorCode::INVALID_KEY_BLOB.  Note that a key
+     * with a zero-length APPLICATION_DATA cannot have its key characteristics retrieved using
+     * getKeyCharacteristics() due to a historical limitation of the API.
      *
      * The content of this tag must be bound to the key cryptographically, meaning it must not be
      * possible for an adversary who has access to all of the secure world secrets but does not have