Using the VC4 drivers with Qt and Raspberry pi 3

ronpetit

Hello, following this guide https://wiki.qt.io/RaspberryPi2EGLFS, I managed to cross compile Qt 5.10.1, only the qtbase, and the qtsvg (I only need those), and as I wanted to use the VC4 drivers for hardware acceleration, I used the device "linux-rasp-pi3-vc4-g++", everything went fine on the compilation.

I compiled also the qopenglwidget to test everything, but after activating the vc4 driver on the raspi-config menu, I got the following error:

failed to add service - already in use?

Searching on the internet, everybody suggest to disable the vc4 drivers to get rid of the error, but if I do that, then, the eglfs will complain that it cannot find any DRM device. So, how can I use the vc4 drivers with Qt?

Details:
Host machine: ubuntu 16.04, 64bits, amd64 ARCH (don't know if this really matter)
RPi: Raspberry pi 3 model B running raspbian JESSIE, and using the latest kernel (4.14)

Any help will be highly appreciated

Cleiton Bueno

@ronpetit put here the output of the file: config.summary

Cleiton Bueno

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ronpetit

@Cleiton-Bueno Check it

Building on: linux-g++ (x86_64, CPU features: mmx sse sse2)
Building for: devices/linux-rasp-pi3-vc4-g++ (arm, CPU features: <none>)
Configuration: cross_compile use_gold_linker compile_examples enable_new_dtags largefile precompile_header shared rpath release c++11 concurrent dbus reduce_exports stl
Build options:
  Mode ................................... release
  Optimize release build for size ........ no
  Building shared libraries .............. yes
  Using C++ standard ..................... C++11
  Using ccache ........................... no
  Using gold linker ...................... yes
  Using new DTAGS ........................ yes
  Using precompiled headers .............. yes
  Using LTCG ............................. no
  Target compiler supports:
    NEON ................................. no
  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
  QML debugging .......................... yes
  udev ................................... yes
  Using system zlib ...................... yes
Qt Core:
  DoubleConversion ....................... yes
    Using system DoubleConversion ........ no
  GLib ................................... yes
  iconv .................................. no
  ICU .................................... yes
  Logging backends:
    journald ............................. no
    syslog ............................... no
    slog2 ................................ no
  Using system PCRE2 ..................... no
Qt Network:
  getifaddrs() ........................... yes
  IPv6 ifname ............................ yes
  libproxy ............................... no
  OpenSSL ................................ yes
    Qt directly linked to OpenSSL ........ no
  OpenSSL 1.1 ............................ yes
  SCTP ................................... no
  Use system proxies ..................... yes
Qt Gui:
  Accessibility .......................... yes
  FreeType ............................... yes
    Using system FreeType ................ yes
  HarfBuzz ............................... yes
    Using system HarfBuzz ................ no
  Fontconfig ............................. yes
  Image formats:
    GIF .................................. yes
    ICO .................................. yes
    JPEG ................................. yes
      Using system libjpeg ............... yes
    PNG .................................. yes
      Using system libpng ................ yes
  EGL .................................... yes
  OpenVG ................................. yes
  OpenGL:
    Desktop OpenGL ....................... no
    OpenGL ES 2.0 ........................ yes
    OpenGL ES 3.0 ........................ no
    OpenGL ES 3.1 ........................ no
    OpenGL ES 3.2 ........................ no
  Vulkan ................................. no
  Session Management ..................... yes
Features used by QPA backends:
  evdev .................................. yes
  libinput ............................... yes
  INTEGRITY HID .......................... no
  mtdev .................................. yes
  tslib .................................. yes
  xkbcommon-evdev ........................ 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 ...................... no
    EGLFS GBM ............................ yes
    EGLFS Mali ........................... no
    EGLFS Raspberry Pi ................... yes
    EGL on X11 ........................... no
  LinuxFB ................................ yes
  VNC .................................... yes
  Mir client ............................. no
  X11:
    Using system-provided XCB libraries .. yes
    EGL on X11 ........................... no
    Xinput2 .............................. yes
    XCB XKB .............................. yes
    XLib ................................. yes
    XCB render ........................... yes
    XCB GLX .............................. yes
    XCB Xlib ............................. yes
    Using system-provided xkbcommon ...... no
    Native painting (experimental) ....... yes
Qt Widgets:
  GTK+ ................................... no
  Styles ................................. Fusion Windows
Qt PrintSupport:
  CUPS ................................... yes
Qt Sql:
  DB2 (IBM) .............................. no
  InterBase .............................. no
  MySql .................................. yes
  OCI (Oracle) ........................... no
  ODBC ................................... yes
  PostgreSQL ............................. yes
  SQLite2 ................................ yes
  SQLite ................................. yes
    Using system provided SQLite ......... no
  TDS (Sybase) ........................... yes

Note: Also available for Linux: linux-clang linux-icc

Note: PKG_CONFIG_LIBDIR automatically set to /home/ron/raspi5.10/sysroot/usr/lib/pkgconfig:/home/ron/raspi5.10/sysroot/usr/share/pkgconfig:/home/ron/raspi5.10/sysroot/usr/lib/arm-linux-gnueabihf/pkgconfig

Note: PKG_CONFIG_SYSROOT_DIR automatically set to /home/ron/raspi5.10/sysroot

Note: Dropped compiler flags '-pthread' when detecting library 'glib'.

Cleiton Bueno

@ronpetit said in Using the VC4 drivers with Qt and Raspberry pi 3:

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 ...................... no
EGLFS GBM ............................ yes
EGLFS Mali ........................... no
EGLFS Raspberry Pi ................... yes
EGL on X11 ........................... no

As for qtbase it seems OK.

  OpenGL:
    Desktop OpenGL ....................... no
    OpenGL ES 2.0 ........................ 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 ...................... no
    EGLFS GBM ............................ yes
    EGLFS Mali ........................... no
    EGLFS Raspberry Pi ................... yes
    EGL on X11 ........................... no

How is gpu_mem set up in /boot/config.txt?

If you have vc4-kms-v3d configured in dtoverlay, I had problems with this device-tree using Wayland.

It would be enriching more information using vcgencmd, especially with the trace part.

But I do not see problems or malfunction on the Qt side with this reported message.

Cleiton Bueno

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