fix: DualShock4 and DualSense improvements

docs/platform-support.md

@@ -138,6 +138,20 @@ and control channels. Numbered control-channel output is normalized before
 parsing, whether the kernel includes the report number in the payload or
 provides it separately on the UHID event.
 
+The default DualShock 4 and DualSense profiles use Bluetooth framing, avoiding
+the parent-USB checks that can make virtual USB devices appear late in Steam.
+Explicit USB and Bluetooth factories remain available for consumers that
+require a particular transport. DualShock 4 Bluetooth input reports set the
+HID-present header flag required by HIDAPI consumers and include the transport
+CRC, so a running consumer can accept live input after hotplug. DualSense motion
+packing preserves the public meters-per-second-squared and degrees-per-second
+units while applying the same
+raw sensor calibration used by Inputtino. Periodic PlayStation reports are
+repacked at 100 Hz so their sequence number and sensor timestamp continue to
+advance even when controller state is unchanged. Periodic and application
+submissions are serialized so a repeated report cannot restore stale motion
+state after a newer application report.
+
 The backend opens `/dev/uhid` in nonblocking mode, matching the original
 asynchronous gamepad registration path. Its event reader is active before
 device registration begins, and creation does not report success until the
@@ -147,9 +161,8 @@ a controller before its kernel HID device has started.
 
 On Linux, DualShock 4 and DualSense emit Sony's native `Wireless Controller`
 product name for Steam HID discovery. The requested USB or Bluetooth bus,
-descriptor, and report framing remain unchanged; in particular, the default
-DualShock 4 profile stays on its USB report contract. This transport-only name
-is confined to the Linux backend; public profile names, Windows names, and VHF
+descriptor, and report framing remain unchanged. This transport-only name is
+confined to the Linux backend; public profile names, Windows names, and VHF
 behavior are unchanged.
 
 Switch Pro keeps its Nintendo identity on the Linux uinput path. This follows

docs/usage.md

@@ -217,6 +217,10 @@ Consumers may replace `DeviceProfile::name` before creating a gamepad, for
 example, to prepend an application name while preserving the default controller
 identity across platform backends.
 
+`profiles::dualshock4()` and `profiles::dualsense()` select Bluetooth framing
+for reliable native-controller discovery. Consumers can use the corresponding
+`_usb()` or `_bluetooth()` factory when the transport must be explicit.
+
 The platform-neutral Generic HID descriptor reports the D-pad as buttons 13
 through 16 in the input report. Linux may still route that profile through
 `uinput`, where the backend exposes those same logical directions through the

src/core/profiles.cpp

@@ -2095,7 +2095,7 @@ namespace lvh::profiles {
   }
 
   DeviceProfile dualshock4() {
-    return dualshock4_usb();
+    return dualshock4_bluetooth();
   }
 
   DeviceProfile dualshock4_usb() {
@@ -2107,7 +2107,7 @@ namespace lvh::profiles {
   }
 
   DeviceProfile dualsense() {
-    return dualsense_usb();
+    return dualsense_bluetooth();
   }
 
   DeviceProfile dualsense_usb() {

src/core/report.cpp

@@ -6,11 +6,13 @@
 // standard includes
 #include <algorithm>
 #include <array>
+#include <atomic>
 #include <chrono>
 #include <cmath>
 #include <cstddef>
 #include <cstdint>
 #include <cstring>
+#include <numbers>
 #include <optional>
 #include <span>
 #include <utility>
@@ -31,6 +33,8 @@ namespace lvh::reports {
 
     constexpr auto dualshock4_bt_input_report_id = std::byte {0x11};
 
+    constexpr auto dualshock4_bt_input_hid_present = std::byte {0x80};
+
     constexpr auto dualshock4_bt_output_report_id = std::byte {0x11};
 
     constexpr auto dualshock4_output_hwctl_crc32 = std::byte {0x40};
@@ -61,6 +65,10 @@ namespace lvh::reports {
 
     constexpr auto dualsense_flag2_compatible_vibration = std::byte {0x04};
 
+    constexpr auto dualsense_acceleration_scale = 9.80665F * 100.0F;
+
+    constexpr auto dualsense_gyroscope_scale = 1145.0F * std::numbers::pi_v<float> / 180.0F;
+
     constexpr std::uint8_t switch_rumble_and_subcommand_output_report_id = 0x01;
 
     constexpr std::uint8_t switch_rumble_only_output_report_id = 0x10;
@@ -613,6 +621,19 @@ namespace lvh::reports {
       return static_cast<std::uint16_t>((static_cast<std::uint64_t>(elapsed) * 3U) / 16U);
     }
 
+    std::uint8_t dualsense_sequence_number() {
+      static std::atomic_uint32_t sequence_number = 0;
+      return static_cast<std::uint8_t>((sequence_number.fetch_add(1U, std::memory_order_relaxed) + 1U) % 255U);
+    }
+
+    std::uint32_t dualsense_sensor_timestamp() {
+      const auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(
+                             std::chrono::steady_clock::now().time_since_epoch()
+      )
+                             .count();
+      return static_cast<std::uint32_t>(static_cast<std::uint64_t>(elapsed) / 333U);
+    }
+
     std::vector<std::uint8_t> pack_dualshock4_input_report(const DeviceProfile &profile, const GamepadState &state) {
       const auto is_bluetooth = profile.bus_type == BusType::bluetooth;
       const auto payload_offset = is_bluetooth ? 3U : 1U;
@@ -627,6 +648,9 @@ namespace lvh::reports {
 
       ByteReport report(profile.input_report_size, zero_byte);
       report[0] = is_bluetooth ? dualshock4_bt_input_report_id : to_byte(profile.report_id);
+      if (is_bluetooth) {
+        report[1] = dualshock4_bt_input_hid_present;
+      }
 
       report[payload_offset + 0U] = to_byte(normalize_u8_axis(normalized.left_stick.x));
       report[payload_offset + 1U] = to_byte(normalize_u8_axis(-normalized.left_stick.y));
@@ -722,6 +746,7 @@ namespace lvh::reports {
       report[payload_offset + 3U] = to_byte(normalize_u8_axis(-normalized.right_stick.y));
       report[payload_offset + 4U] = to_byte(normalize_trigger(normalized.left_trigger));
       report[payload_offset + 5U] = to_byte(normalize_trigger(normalized.right_trigger));
+      report[payload_offset + 6U] = to_byte(dualsense_sequence_number());
       report[payload_offset + 7U] = to_byte(hat_from_buttons(normalized.buttons));
 
       if (normalized.buttons.test(GamepadButton::x)) {
@@ -773,15 +798,16 @@ namespace lvh::reports {
       }
 
       if (normalized.gyroscope) {
-        write_i16(report, payload_offset + 15U, scale_i16(normalized.gyroscope->x, 1145.0F));
-        write_i16(report, payload_offset + 17U, scale_i16(normalized.gyroscope->y, 1145.0F));
-        write_i16(report, payload_offset + 19U, scale_i16(normalized.gyroscope->z, 1145.0F));
+        write_i16(report, payload_offset + 15U, scale_i16(normalized.gyroscope->x, dualsense_gyroscope_scale));
+        write_i16(report, payload_offset + 17U, scale_i16(normalized.gyroscope->y, dualsense_gyroscope_scale));
+        write_i16(report, payload_offset + 19U, scale_i16(normalized.gyroscope->z, dualsense_gyroscope_scale));
       }
       if (normalized.acceleration) {
-        write_i16(report, payload_offset + 21U, scale_i16(normalized.acceleration->x, 100.0F));
-        write_i16(report, payload_offset + 23U, scale_i16(normalized.acceleration->y, 100.0F));
-        write_i16(report, payload_offset + 25U, scale_i16(normalized.acceleration->z, 100.0F));
+        write_i16(report, payload_offset + 21U, scale_i16(normalized.acceleration->x, dualsense_acceleration_scale));
+        write_i16(report, payload_offset + 23U, scale_i16(normalized.acceleration->y, dualsense_acceleration_scale));
+        write_i16(report, payload_offset + 25U, scale_i16(normalized.acceleration->z, dualsense_acceleration_scale));
       }
+      write_u32(report, payload_offset + 27U, dualsense_sensor_timestamp());
 
       write_dualsense_touch_contact(report, payload_offset + 32U, normalized.touchpad_contacts[0]);
       write_dualsense_touch_contact(report, payload_offset + 36U, normalized.touchpad_contacts[1]);

src/include/libvirtualhid/profiles.hpp

@@ -44,7 +44,11 @@ namespace lvh::profiles {
   /**
    * @brief Create the PlayStation DualShock 4-compatible gamepad profile.
    *
-   * @return Default DualShock 4-compatible device profile.
+   * The default uses Bluetooth framing because Linux native-controller
+   * consumers discover virtual DualShock 4 devices more reliably through that
+   * transport. Use `dualshock4_usb()` when USB framing is explicitly required.
+   *
+   * @return Bluetooth DualShock 4-compatible device profile.
    */
   DeviceProfile dualshock4();
 
@@ -65,7 +69,11 @@ namespace lvh::profiles {
   /**
    * @brief Create the PlayStation DualSense-compatible gamepad profile.
    *
-   * @return Default DualSense-compatible device profile.
+   * The default uses Bluetooth framing because Linux native-controller
+   * consumers discover virtual DualSense devices more reliably through that
+   * transport. Use `dualsense_usb()` when USB framing is explicitly required.
+   *
+   * @return Bluetooth DualSense-compatible device profile.
    */
   DeviceProfile dualsense();
 

src/platform/linux/uhid_backend.cpp

@@ -2815,8 +2815,8 @@ namespace lvh::detail {
         std::memcpy(request.rd_data, options.profile.report_descriptor.data(), options.profile.report_descriptor.size());
         profile_ = options.profile;
         {
-          std::lock_guard lock {report_mutex_};
-          last_report_ = reports::pack_input_report(profile_, {});
+          std::lock_guard lock {state_mutex_};
+          last_state_ = {};
         }
 
         {
@@ -2848,25 +2848,13 @@ namespace lvh::detail {
       }
 
       OperationStatus submit(
-        const GamepadState & /*state*/,
+        const GamepadState &state,
         const std::vector<std::uint8_t> &report
       ) override {
-        if (!open_) {
-          return OperationStatus::failure(ErrorCode::device_closed, "UHID gamepad is closed");
-        }
-
-        uhid_event event {};
-        if (report.size() > sizeof(event.u.input2.data)) {
-          return OperationStatus::failure(ErrorCode::invalid_argument, "HID input report is too large for UHID");
-        }
-
-        event.type = UHID_INPUT2;
-        event.u.input2.size = static_cast<std::uint16_t>(report.size());
-        std::memcpy(event.u.input2.data, report.data(), report.size());
-        auto status = write_event(event);
+        std::lock_guard lock {state_mutex_};
+        auto status = write_input_report(report);
         if (status.ok()) {
-          std::lock_guard lock {report_mutex_};
-          last_report_ = report;
+          last_state_ = state;
         }
         return status;
       }
@@ -2922,6 +2910,22 @@ namespace lvh::detail {
       }
 
     private:
+      OperationStatus write_input_report(const std::vector<std::uint8_t> &report) {
+        if (!open_) {
+          return OperationStatus::failure(ErrorCode::device_closed, "UHID gamepad is closed");
+        }
+
+        uhid_event event {};
+        if (report.size() > sizeof(event.u.input2.data)) {
+          return OperationStatus::failure(ErrorCode::invalid_argument, "HID input report is too large for UHID");
+        }
+
+        event.type = UHID_INPUT2;
+        event.u.input2.size = static_cast<std::uint16_t>(report.size());
+        std::memcpy(event.u.input2.data, report.data(), report.size());
+        return write_event(event);
+      }
+
       OperationStatus write_event(const uhid_event &event) {
         using enum ErrorCode;
 
@@ -3042,13 +3046,10 @@ namespace lvh::detail {
             break;
           }
 
-          std::vector<std::uint8_t> report;
-          {
-            std::lock_guard lock {report_mutex_};
-            report = last_report_;
-          }
+          std::lock_guard lock {state_mutex_};
+          const auto report = reports::pack_input_report(profile_, last_state_);
           if (!report.empty()) {
-            static_cast<void>(submit({}, report));
+            static_cast<void>(write_input_report(report));
           }
         }
       }
@@ -3173,7 +3174,7 @@ namespace lvh::detail {
       std::string physical_id_;
       std::string unique_id_;
       std::array<std::uint8_t, 6> playstation_mac_address_ {};
-      std::vector<std::uint8_t> last_report_;
+      GamepadState last_state_;
       std::atomic_bool open_ = true;
       std::atomic_bool running_ = false;
       std::jthread reader_;
@@ -3183,7 +3184,7 @@ namespace lvh::detail {
       bool started_ = false;
       bool reader_exited_ = false;
       std::mutex write_mutex_;
-      std::mutex report_mutex_;
+      std::mutex state_mutex_;
       std::mutex callback_mutex_;
       OutputCallback output_callback_;
     };

tests/fixtures/include/fixtures/linux_backend_test_hooks.hpp

@@ -212,9 +212,9 @@ namespace lvh::detail::test {
     bool saw_dualshock4_feature_crc = false;
 
     /**
-     * @brief Whether the peer observed a Bluetooth-framed DualSense input report.
+     * @brief Whether periodic Bluetooth DualSense reports preserved motion and advanced sensor metadata.
      */
-    bool saw_dualsense_bluetooth_input = false;
+    bool saw_dualsense_bluetooth_input_with_live_sensor_metadata = false;
 
     /**
      * @brief Whether the peer observed a Bluetooth-framed DualShock 4 input report.

tests/fixtures/linux_backend_test_hooks.cpp

@@ -1698,13 +1698,42 @@ namespace lvh::detail::test {
     UhidGamepad gamepad {descriptors[0]};
     auto event = create_started_profile_uhid_gamepad(gamepad, 9, options, descriptors[1], BUS_BLUETOOTH, result);
 
+    GamepadState motion_state;
+    motion_state.acceleration = Vector3 {.x = 1.0F, .y = 2.0F, .z = 3.0F};
+    motion_state.gyroscope = Vector3 {.x = 4.0F, .y = 5.0F, .z = 6.0F};
+    const auto submitted_report = reports::pack_input_report(options.profile, motion_state);
+    result.submit_status = gamepad.submit(motion_state, submitted_report);
+
+    bool first_input_report_valid = false;
+    std::uint8_t first_sequence = 0;
+    std::uint32_t first_sensor_timestamp = 0;
+    std::array<std::uint8_t, 12> first_sensor_values {};
     if (read_uhid_event_type(descriptors[1], UHID_INPUT2, event)) {
       const auto report_size = static_cast<std::size_t>(event.u.input2.size);
       if (report_size == options.profile.input_report_size && event.u.input2.data[0] == 0x31) {
         const auto crc_offset = report_size - 4U;
         const auto expected_crc = crc32(std::span<const std::uint8_t> {event.u.input2.data, crc_offset}, playstation_crc_seed(0xA1));
         const auto actual_crc = read_u32_le(event.u.input2.data + crc_offset);
-        result.saw_dualsense_bluetooth_input = expected_crc == actual_crc;
+        std::copy_n(event.u.input2.data + 17U, first_sensor_values.size(), first_sensor_values.begin());
+        first_input_report_valid = expected_crc == actual_crc && std::equal(
+                                                                   first_sensor_values.begin(),
+                                                                   first_sensor_values.end(),
+                                                                   submitted_report.begin() + 17
+                                                                 );
+        first_sequence = event.u.input2.data[8];
+        first_sensor_timestamp = read_u32_le(event.u.input2.data + 29U);
+      }
+    }
+
+    if (read_uhid_event_type(descriptors[1], UHID_INPUT2, event)) {
+      const auto report_size = static_cast<std::size_t>(event.u.input2.size);
+      if (report_size == options.profile.input_report_size && event.u.input2.data[0] == 0x31) {
+        const auto crc_offset = report_size - 4U;
+        const auto expected_crc = crc32(std::span<const std::uint8_t> {event.u.input2.data, crc_offset}, playstation_crc_seed(0xA1));
+        const auto actual_crc = read_u32_le(event.u.input2.data + crc_offset);
+        result.saw_dualsense_bluetooth_input_with_live_sensor_metadata =
+          first_input_report_valid && expected_crc == actual_crc && event.u.input2.data[8] != first_sequence &&
+          read_u32_le(event.u.input2.data + 29U) != first_sensor_timestamp && std::equal(first_sensor_values.begin(), first_sensor_values.end(), event.u.input2.data + 17U);
       }
     }
 
@@ -1732,7 +1761,6 @@ namespace lvh::detail::test {
 
     result.close_status = gamepad.close();
     static_cast<void>(::close(descriptors[1]));
-    result.submit_status = OperationStatus::success();
     return result;
   }
 
@@ -1840,7 +1868,11 @@ namespace lvh::detail::test {
 
     if (read_uhid_event_type(descriptors[1], UHID_INPUT2, event)) {
       const auto report_size = static_cast<std::size_t>(event.u.input2.size);
-      if (report_size == options.profile.input_report_size && event.u.input2.data[0] == 0x11) {
+      if (
+        report_size == options.profile.input_report_size &&
+        event.u.input2.data[0] == 0x11 &&
+        (event.u.input2.data[1] & 0x80U) != 0U
+      ) {
         const auto crc_offset = report_size - 4U;
         const auto expected_crc = crc32(std::span<const std::uint8_t> {event.u.input2.data, crc_offset}, playstation_crc_seed(0xA1));
         const auto actual_crc = read_u32_le(event.u.input2.data + crc_offset);

tests/unit/test_linux_backend.cpp

@@ -822,11 +822,12 @@ TEST_F(LinuxBackendTest, SocketpairBackedDualSenseRepliesToFeatureReports) {
 TEST_F(LinuxBackendTest, SocketpairBackedDualSenseBluetoothFramesReports) {
   const auto result = lvh::detail::test::linux_dualsense_bluetooth_uhid_socketpair_reports();
   EXPECT_TRUE(result.create_status.ok()) << result.create_status.message();
+  EXPECT_TRUE(result.submit_status.ok()) << result.submit_status.message();
   EXPECT_TRUE(result.close_status.ok()) << result.close_status.message();
   EXPECT_TRUE(result.creation.saw_create);
   EXPECT_TRUE(result.creation.waited_for_start);
   EXPECT_EQ(result.creation.name, "Wireless Controller");
-  EXPECT_TRUE(result.saw_dualsense_bluetooth_input);
+  EXPECT_TRUE(result.saw_dualsense_bluetooth_input_with_live_sensor_metadata);
   EXPECT_TRUE(result.saw_dualsense_pairing);
   EXPECT_TRUE(result.saw_dualsense_feature_crc);
 }

tests/unit/test_linux_consumers.cpp

@@ -886,7 +886,7 @@ TEST_F(LinuxConsumerTest, SdlSeesDualShock4UsbControllerBehavior) {
   });
 }
 
-TEST_F(LinuxConsumerTest, SdlSeesDualShock4BluetoothControllerDiscovery) {
+TEST_F(LinuxConsumerTest, SdlSeesDualShock4BluetoothControllerBehavior) {
   ASSERT_TRUE(HasReadableWritableDeviceNode("/dev/uhid"));
 
   run_sdl_playstation_controller_test({
@@ -895,7 +895,6 @@ TEST_F(LinuxConsumerTest, SdlSeesDualShock4BluetoothControllerDiscovery) {
     .stable_id = "02:00:00:00:00:04",
     .minimum_buttons = 10,
     .minimum_axes = 4,
-    .expect_live_input = false,
   });
 }