QtWayland error on Raspberry Pi

[sedlalu2]

Hello,
I want to use wayland as my windowing system. Qt Cross compilation went really ok, without no errors (using Qt5.8 downloaded from download.qt.io).

Cross compilation of qwindow-compositor is without any error too. But when I want to run app on my raspberry Pi, wierd error occures:

QtCompositor: Failed to initialize EGL display. There is no EGL_WL_bind_wayland_display extension.

I have tried to log this error via export QT_LOGGING_RULES=qt.qpa.*=true but that doesnt give me any information while the application
cannot be started:

qt.qpa.egldeviceintegration: EGL device integration plugin keys: ("eglfs_brcm", "eglfs_kms")
qt.qpa.egldeviceintegration: EGL device integration plugin keys (sorted): ("eglfs_brcm", "eglfs_kms")
qt.qpa.egldeviceintegration: Trying to load device EGL integration "eglfs_brcm"
qt.qpa.egldeviceintegration: Using EGL device integration "eglfs_brcm"
[9;0]Unable to query physical screen size, defaulting to 100 dpi.
To override, set QT_QPA_EGLFS_PHYSICAL_WIDTH and QT_QPA_EGLFS_PHYSICAL_HEIGHT (in millimeters).
qt.qpa.input: libinput: input device 'CHICONY USB Keyboard', /dev/input/event0 is tagged by udev as: Keyboard
qt.qpa.input: libinput: input device 'CHICONY USB Keyboard', /dev/input/event0 is a keyboard
qt.qpa.input: libinput: input device 'CHICONY USB Keyboard', /dev/input/event1 is tagged by udev as: Keyboard
qt.qpa.input: libinput: input device 'CHICONY USB Keyboard', /dev/input/event1 is a keyboard
qt.qpa.input: Using xkbcommon for key mapping
QtCompositor: Failed to initialize EGL display. There is no EGL_WL_bind_wayland_display extension.

Can you help me with this error, please?

Using Raspberry Pi 3B with raspbian. Cross compilation was performed with config options:

-opengl
es2
-optimized-qmake
-no-pch
-make
libs
-make
tools
-reduce-exports
-sysroot
/home/lukas/raspberry/sysroot
-device
linux-rasp-pi2-g++
-device-option
CROSS_COMPILE=/home/lukas/raspberry/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin/arm-linux-gnueabihf-
-prefix
/usr/local/rasp
-opensource
-nomake
examples
-nomake
tests
-confirm-license
-skip
qtwebengine
-skip
qtsensors
-skip
qtgamepad
-skip
qtmacextras
-skip
qtandroidextras
-prefix
/usr/local/qt5pi
-extprefix
/home/lukas/raspi/qt5pi
-hostprefix
/home/lukas/raspi/qt5

[Cleiton Bueno]

Did you export XDG_RUNTIME?

Try:

mkdir $HOME/.xdg
export XDG_RUNTIME_DIR=$HOME/.xdg
export QT_QPA_PLATFORM=wayland-brcm
/home/user/your-app-qt -platform eglfs &

Or:

mkdir $HOME/.xdg
export XDG_RUNTIME_DIR=$HOME/.xdg

wayland-compositor &
/home/user/your-app-qt -platform wayland

I hope it helps!

---

Cleiton Bueno

Blog | Linkedin | B2Open

[sedlalu2]

Thanks for the answer!

I have tried that but the error still occurs. I have already tried to use previous version 5.7 of Qt but the result is not different at all.

[sneubert]

Hi sedlalu2,

the only way I got the raspberry pi (3 in my case) to work with wayland and egl was to use the vc4 driver.
Additional I hade to cross-compile qt with the mkspec for linux-rasp-pi3-g++ and changed EGLFS_DEVICE_INTEGRATION
in qmake.conf to eglfs_kms. Then I had to adjust the symlinks for libEGL.so and libGLESv2.so from /opt/vc/lib
to /usr/lib/arm-linux-gnueabihf.

Using vc4 has no notable drawback compared using the eglfs_brcm device integration, but the performance is
very poor on weston and even worse on the qtwayland compositors.