Raspberry pi 4 rotate touchscreen 90 degrees

[Walter-X]

I've a raspberry pi 4 and cross compile qt for it and can start a Qt Quick application. That works well.

But I have to rotate the screen and touchscreen to portrait mode. The raspberry documentation said: "If using the VC4 FKMS V3D driver (this is the default on the Raspberry Pi 4), then 90 and 270 degree rotations are not supported. The Screen Configuration utility provides display rotations for this driver."

Without VC4 FKMS V3D driver the compilation failed and the Qt application can't start and with VC4 FKMS V3D driver I can't rotate the screen.

Is there any solution to solve this problem?

[sneubert]

I know this is bad, but we rotated the application :-)

[Walter-X]

Thank you. I'll give this a try.