EGLFS Full Screen issue on Raspberry Pi 4 Desktop

[cosmonaut65]

Hi,

I've cross-compiled Qt 5.15.0 using the instructions provided here:
https://www.interelectronix.com/de/qt-auf-dem-raspberry-pi-4.html (with the help of Google Translate)

When I compiled the example "alarms" app and copied it to the Raspberry Pi, it ran but it was windowed. I was using it with the desktop enabled. When I configured the Pi to boot straight to CLI, the issue was gone and it ran full screen as I wanted.
To try get it to work while in Desktop mode, I booted back into desktop and ran it with the eglfs flag i.e.:

./alarms -platform eglfs

When I did this, it didn't run and I got the following errors on the terminal

Failed to move cursor on screen HDMI1: -13
Failed to move cursor on screen HDMI1: -13
Could not set cursor on screen HDMI1: -13
failed to export dumb buffer: Permission denied
Failed to create scanout resource
failed to export dumb buffer: Permission denied
Failed to create scanout resource
QEGLPlatformContext: eglSwapBuffers failed: 3003
Could not lock GBM surface front buffer!

If it helps, this was the output of my config when I was cross-compiling Qt 5.15:

Build options:
  Mode ................................... release
  Optimize release build for size ........ no
  Building shared libraries .............. yes
  Using C standard ....................... C11
  Using C++ standard ..................... C++17
  Using ccache ........................... no
  Using new DTAGS ........................ yes
  Relocatable ............................ yes
  Using precompiled headers .............. yes
  Using LTCG ............................. no
  Target compiler supports:
    NEON ................................. yes
  Build parts ............................ libs
Qt modules and options:
  Qt Concurrent .......................... yes
  Qt D-Bus ............................... yes
  Qt D-Bus directly linked to libdbus .... yes
  Qt Gui ................................. yes
  Qt Network ............................. yes
  Qt Sql ................................. yes
  Qt Testlib ............................. yes
  Qt Widgets ............................. yes
  Qt Xml ................................. yes
Support enabled for:
  Using pkg-config ....................... yes
  udev ................................... yes
  Using system zlib ...................... yes
  Zstandard support ...................... no
Qt Core:
  DoubleConversion ....................... yes
    Using system DoubleConversion ........ yes
  GLib ................................... yes
  iconv .................................. no
  ICU .................................... yes
  Built-in copy of the MIME database ..... yes
  Tracing backend ........................ <none>
  Logging backends:
    journald ............................. no
    syslog ............................... no
    slog2 ................................ no
  PCRE2 .................................. yes
    Using system PCRE2 ................... yes
Qt Network:
  getifaddrs() ........................... yes
  IPv6 ifname ............................ yes
  libproxy ............................... no
  Linux AF_NETLINK ....................... yes
  OpenSSL ................................ yes
    Qt directly linked to OpenSSL ........ no
  OpenSSL 1.1 ............................ yes
  DTLS ................................... yes
  OCSP-stapling .......................... yes
  SCTP ................................... no
  Use system proxies ..................... yes
  GSSAPI ................................. no
Qt Gui:
  Accessibility .......................... yes
  FreeType ............................... yes
    Using system FreeType ................ yes
  HarfBuzz ............................... yes
    Using system HarfBuzz ................ yes
  Fontconfig ............................. yes
  Image formats:
    GIF .................................. yes
    ICO .................................. yes
    JPEG ................................. yes
      Using system libjpeg ............... yes
    PNG .................................. yes
      Using system libpng ................ yes
  Text formats:
    HtmlParser ........................... yes
    CssParser ............................ yes
    OdfWriter ............................ yes
    MarkdownReader ....................... yes
      Using system libmd4c ............... no
    MarkdownWriter ....................... yes
  EGL .................................... yes
  OpenVG ................................. no
  OpenGL:
    Desktop OpenGL ....................... no
    OpenGL ES 2.0 ........................ yes
    OpenGL ES 3.0 ........................ yes
    OpenGL ES 3.1 ........................ yes
    OpenGL ES 3.2 ........................ yes
  Vulkan ................................. yes
  Session Management ..................... yes
Features used by QPA backends:
  evdev .................................. yes
  libinput ............................... yes
  INTEGRITY HID .......................... no
  mtdev .................................. yes
  tslib .................................. yes
  xkbcommon .............................. yes
  X11 specific:
    XLib ................................. yes
    XCB Xlib ............................. yes
    EGL on X11 ........................... yes
    xkbcommon-x11 ........................ yes
QPA backends:
  DirectFB ............................... no
  EGLFS .................................. yes
  EGLFS details:
    EGLFS OpenWFD ........................ no
    EGLFS i.Mx6 .......................... no
    EGLFS i.Mx6 Wayland .................. no
    EGLFS RCAR ........................... no
    EGLFS EGLDevice ...................... yes
    EGLFS GBM ............................ yes
    EGLFS VSP2 ........................... no
    EGLFS Mali ........................... no
    EGLFS Raspberry Pi ................... no
    EGLFS X11 ............................ yes
  LinuxFB ................................ yes
  VNC .................................... yes
  XCB:
    Using system-provided xcb-xinput ..... no
    Native painting (experimental) ....... no
    GL integrations:
      GLX Plugin ......................... no
      EGL-X11 Plugin ..................... yes
Qt Sql:
  SQL item models ........................ yes
Qt Widgets:
  GTK+ ................................... no
  Styles ................................. Fusion Windows
Qt PrintSupport:
  CUPS ................................... yes
Qt Sql Drivers:
  DB2 (IBM) .............................. no
  InterBase .............................. no
  MySql .................................. no
  OCI (Oracle) ........................... no
  ODBC ................................... yes
  PostgreSQL ............................. yes
  SQLite2 ................................ no
  SQLite ................................. yes
    Using system provided SQLite ......... no
  TDS (Sybase) ........................... yes
Qt Testlib:
  Tester for item models ................. yes
Serial Port:
  ntddmodm ............................... no
Qt SerialBus:
  Socket CAN ............................. yes
  Socket CAN FD .......................... yes
  SerialPort Support ..................... yes
Further Image Formats:
  JasPer ................................. no
  MNG .................................... no
  TIFF ................................... yes
    Using system libtiff ................. yes
  WEBP ................................... yes
    Using system libwebp ................. yes
Qt QML:
  QML network support .................... yes
  QML debugging and profiling support .... yes
  QML just-in-time compiler .............. yes
  QML sequence object .................... yes
  QML XML http request ................... yes
  QML Locale ............................. yes
Qt QML Models:
  QML list model ......................... yes
  QML delegate model ..................... yes
Qt Quick:
  Direct3D 12 ............................ no
  AnimatedImage item ..................... yes
  Canvas item ............................ yes
  Support for Qt Quick Designer .......... yes
  Flipable item .......................... yes
  GridView item .......................... yes
  ListView item .......................... yes
  TableView item ......................... yes
  Path support ........................... yes
  PathView item .......................... yes
  Positioner items ....................... yes
  Repeater item .......................... yes
  ShaderEffect item ...................... yes
  Sprite item ............................ yes
QtQuick3D:
  Assimp ................................. yes
  System Assimp .......................... no
Qt Scxml:
  ECMAScript data model for QtScxml ...... yes
Qt Gamepad:
  SDL2 ................................... no
Qt 3D:
  Assimp ................................. yes
  System Assimp .......................... no
  Output Qt3D GL traces .................. no
  Use SSE2 instructions .................. no
  Use AVX2 instructions .................. no
  Aspects:
    Render aspect ........................ yes
    Input aspect ......................... yes
    Logic aspect ......................... yes
    Animation aspect ..................... yes
    Extras aspect ........................ yes
Qt 3D Renderers:
  OpenGL Renderer ........................ yes
  RHI Renderer ........................... no
Qt 3D GeometryLoaders:
  Autodesk FBX ........................... no
Qt Bluetooth:
  BlueZ .................................. yes
  BlueZ Low Energy ....................... yes
  Linux Crypto API ....................... yes
  Native Win32 Bluetooth ................. no
  WinRT Bluetooth API (desktop & UWP) .... no
  WinRT advanced bluetooth low energy API (desktop & UWP) . no
Qt Sensors:
  sensorfw ............................... no
Qt Quick Controls 2:
  Styles ................................. Default Fusion Imagine Material Universal
Qt Quick Templates 2:
  Hover support .......................... yes
  Multi-touch support .................... yes
Qt Positioning:
  Gypsy GPS Daemon ....................... no
  WinRT Geolocation API .................. no
Qt Location:
  Qt.labs.location experimental QML plugin . yes
  Geoservice plugins:
    OpenStreetMap ........................ yes
    HERE ................................. yes
    Esri ................................. yes
    Mapbox ............................... yes
    MapboxGL ............................. yes
    Itemsoverlay ......................... yes
QtXmlPatterns:
  XML schema support ..................... yes
Qt Multimedia:
  ALSA ................................... yes
  GStreamer 1.0 .......................... yes
  GStreamer 0.10 ......................... no
  Video for Linux ........................ yes
  OpenAL ................................. yes
  PulseAudio ............................. yes
  Resource Policy (libresourceqt5) ....... no
  Windows Audio Services ................. no
  DirectShow ............................. no
  Windows Media Foundation ............... no
Qt TextToSpeech:
  Flite .................................. no
  Flite with ALSA ........................ no
  Speech Dispatcher ...................... no
Qt Tools:
  Qt Assistant ........................... yes
  Qt Designer ............................ yes
  Qt Distance Field Generator ............ yes
  kmap2qmap .............................. yes
  Qt Linguist ............................ yes
  Mac Deployment Tool .................... no
  makeqpf ................................ yes
  pixeltool .............................. yes
  qdbus .................................. yes
  qev .................................... yes
  Qt Attributions Scanner ................ yes
  qtdiag ................................. yes
  qtpaths ................................ yes
  qtplugininfo ........................... yes
  Windows deployment tool ................ no
  WinRT Runner Tool ...................... no
Qt Tools:
  QDoc ................................... no

Any solution to this?

Thanks!

[Pablo J. Rogina]

@cosmonaut65 said in EGLFS Full Screen issue on Raspberry Pi 4 Desktop:

To try get it to work while in Desktop mode, I booted back into desktop and ran it with the eglfs flag i.e.:

I guess the options are mutually exclusive; i.e. if in "Desktop mode" (I assume you have X Window manager running) you can't have a Qt app running full screen with EGLFS backend...

[cosmonaut65]

@Pablo-J-Rogina said in EGLFS Full Screen issue on Raspberry Pi 4 Desktop:

@cosmonaut65 said in EGLFS Full Screen issue on Raspberry Pi 4 Desktop:

To try get it to work while in Desktop mode, I booted back into desktop and ran it with the eglfs flag i.e.:

I guess the options are mutually exclusive; i.e. if in "Desktop mode" (I assume you have X Window manager running) you can't have a Qt app running full screen with EGLFS backend...

Thanks for the reply!

Perhaps that is so. With previous builds of Qt (5.12/5.10) on an older Raspberry Pi 3, the apps would always run full screen regardless of whether I was booted into the Desktop or CLI. This makes me think it might be possible to configure the app to launch bypassing the X Window Manager, unless the configuration of EGLFS needed for the Raspberry Pi 4 somehow prevents it.
I'm not too familiar with EGLFS or the behaviour of the X Window Manager, so it's only speculation.

For the time being, booting into the CLI will have to do I guess

[Pablo J. Rogina]

@cosmonaut65 said in EGLFS Full Screen issue on Raspberry Pi 4 Desktop:

For the time being, booting into the CLI will have to do I guess

is your issue solved then? if so please don't forget to mark your post as such. Thanks.