Priority: P2: Important
Affects Version/s: 5.15.0, 5.15.1, 5.15.2, 5.15.3
Fix Version/s: None
Component/s: QPA: EGLFS
Environment:K767 flytech monitor
eglfs (kms integration)
We ported an app from Qt 5.14.X to Qt 5.15 in a yocto image and everything i working fine, except when we connect an external screen in clone mode, both sreens start to flicker and they becore very unresponsive.
The probleme can be reproduce with any of the example app if you configure the output in clone mode.
We want to have the Qt 5.15 LTS version in our project. The version Qt 5.14.2 is working fines, and every version in Qt 5.15.X have the issue.
In the output of the app, we can see a new warning appearing that was not present in the version 5.14:
According to the following documentation:
I think the version 5.15 introduce a call to swapBuffer somewhere, which causes our app to have this behavior.
We use a yocto image (dunfell) build with meta-qt5 (lts-5.15). The Qt configuration is in the attached files. We used:
The eglfskms.json file used for screen cloning:
The environnement variables exported:
I also included in the attached files the output of the app.
If you need anything else, let me know.