.. _changelog_ide_v4_4_2:

v4.4.2
======

v4.4.2 overhauls the USB serial protocol to eliminate the zero-length-packet
overlap that could stall or disconnect the camera, adds a per-board USB
high-speed mode, and fixes the Windows driver installer. It is built on
Qt Creator 14.0.2, unchanged from the previous release, and contains no
breaking changes.

.. contents:: On this page
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   :depth: 1

Highlights
----------

- **USB serial protocol rework** removes the zero-length-packet (ZLP) overlap
  that corrupted synchronization and caused the camera to stall or disconnect.
- **Per-board USB high-speed mode** selects the correct bulk-endpoint size
  (512 vs 64) at connect time.
- **More responsive live view** from tighter framebuffer and state polling
  intervals.
- **Windows driver installer fix** so a USB-driver step no longer fails the
  whole IDE install.
- **Windows read-stall recovery** is re-enabled while dropping the
  ``GET_STATE`` ping workaround that was itself causing stalls.

New features
------------

- **Per-board high-speed flag.** ``firmware/settings.json`` gains a
  ``highSpeed`` entry per board so the IDE picks the correct USB endpoint size
  at connect time. RT1062, AE3, N6, Portenta, and Nicla Vision are flagged
  high-speed while the F4/F7/H7 cameras and Giga remain full-speed; the IDE
  applies the matched board's value via ``setHighSpeed()`` on open, defaulting
  to full-speed (`431fc7bd4
  <https://github.com/openmv/qt-creator/commit/431fc7bd4>`__).

Other changes and improvements
------------------------------

- **Tightened polling intervals** for a more responsive live view: the
  frame-size dump spacing drops from 50 ms to 5 ms, the TX-buffer spacing from
  20 ms to 5 ms, and the get-state spacing settles at 16 ms
  (`431fc7bd4 <https://github.com/openmv/qt-creator/commit/431fc7bd4>`__,
  `c8c14006a <https://github.com/openmv/qt-creator/commit/c8c14006a>`__).
- **Removed unusable code-navigation actions** from the editor, including
  ``Find Usages``, ``Rename Symbol``, and the *in Next Split* follow-symbol and
  follow-type variants, along with their shortcuts (``Ctrl+Shift+U`` /
  ``Ctrl+Shift+R``) and context-menu entries (`2a28fba9b
  <https://github.com/openmv/qt-creator/commit/2a28fba9b>`__).

Bug fixes
---------

- Reworked the USB serial protocol to eliminate the zero-length-packet (ZLP)
  overlap that corrupted synchronization and caused the camera to stall or
  disconnect. Transfers that land on a USB bulk-endpoint boundary are now
  padded or trimmed against the endpoint size, and a per-board USB high-speed
  mode was added (`431fc7bd4
  <https://github.com/openmv/qt-creator/commit/431fc7bd4>`__,
  `79f452128 <https://github.com/openmv/qt-creator/commit/79f452128>`__,
  `1be51d27f <https://github.com/openmv/qt-creator/commit/1be51d27f>`__,
  `cac187991 <https://github.com/openmv/qt-creator/commit/cac187991>`__).
- Re-enabled the Windows read-stall recovery path, where the OS receives data
  but withholds it from the application, while dropping the ``GET_STATE`` ping
  workaround that was itself causing stalls; a new
  ``-override_read_stall_timeout`` command-line option (milliseconds to wait
  before pinging, default 1000) was added to tune the recovery timeout
  (`cac187991 <https://github.com/openmv/qt-creator/commit/cac187991>`__).
- Fixed the Windows USB-driver installer so it no longer fails the whole IDE
  install: the driver ``.cmd`` scripts now exit with success and the installer
  accepts those exit codes (`750560aac
  <https://github.com/openmv/qt-creator/commit/750560aac>`__,
  `ba8537fa5 <https://github.com/openmv/qt-creator/commit/ba8537fa5>`__).

Platform and tool support
-------------------------

- **Qt Creator base:** 14.0.2.

Breaking changes
----------------

None. This release changes no user-facing project workflows.