open gl with qt5 in weston turns black

[brettermeier]

Describe the bug
I tried to build an image for a nano with qt5 and weston. Everything is fine, it booted to the weston desktop and I can start the examples from qt5. When I started the example with opengl, in specific situations the application turns black.
For example:
/usr/share/examples/opengl/qopenglwidget/qopenglwidget --platform wayland-egl
As soon as you try to add a new widget with the button in the left upper corner, the application turns black.
I tested it with an original nano image from nvidia. Started weston with this doc and it worked fine.

To Reproduce
I created an image with https://github.com/OE4T/tegra-demo-distro for a nano, used the branch kirkstone-l4t-r32.7.x and created the image demo-image-weston.
I added meta-qt5 to the bblayers in the conf folder and added

IMAGE_INSTALL:append = " \
         qtbase-plugins \
         qtbase-examples \
         qtwayland \
         "

to layer.conf.

I extended meta-tegra/external/qt5-layer/recipes-qt/qt5/qtbase_%.bbappend with

PACKAGECONFIG:append:tegra = " eglfs kms"
PACKAGECONFIG:append = " gles2 examples eglfs gl widgets"

and added the file meta-tegra/external/qt5-layer/recipes-qt/qt5/qtwayland_%.bbappend
PACKAGECONFIG:remove = "xcomposite-glx"

[dwalkes]

Thanks for the detailed steps to reproduce. I haven't had a chance to try yet yet, however one thing I've noticed when chasing a different issue is that the meta-qt layer for kirkstone (and master) is behind the upstream and missing a few releases. You might try moving to the latest at https://code.qt.io/cgit/qt/qtbase.git/log/?h=5.15 to ensure this hasn't already been found/fixed there.

Also I think it will be important to look for error logs, although I don't exactly know where they'd be in this case. I'd probably just start by dumping dmesg and journalctl to see if there are any clues.

[brettermeier]

Hi, thanks for the fast response.
I tried the version 5.15.11, but it didn't change anything.
Sadly there is no output in dmesg or journalctl.

I tried the example with the official nano sd card image, and it worked fine. The qt version which it installs via apt is much older (5.9.5): That's why I thought this isn't a bug in QT or weston but a configuration problem. But I'm quite unfamiliar with yocto and QT.

[kekiefer]

I guess we have quite a few possibilities here - a problem with Weston, a problem with Qt, a problem with the EGL libraries in L4T, or some combination of these. Unfortunately it's not a simple setup. Here's a few things to try and see if we get any hints.

• do the regular examples included with weston work? how about the weston opengl examples (weston-simple-egl)
• does Qt work on its own in eglfs mode (not running through weston)?
• are there particular Qt examples that do work, maybe some that handle rendering in different ways?
• does a QtWayland-based compositor work better than weston here?

Any further debug information from strace, gdb, or even with WAYLAND_DEBUG enabled might be helpful.

[ichergui]

Hi @brettermeier
Any update on this ?
Otherwise I will close it.