I'm trying to rotate the screen 90 degrees clockwise on X11 running on EfusA9X. Linux built with the fsimx6sx-B2019.11. Buildroot configuration is based on fsimx6sx_std_defconfig with some added (QT5, x11vnc) packages. I use the x11vnc to be able to test on the device remotely.
I was able to rotate the screen successfully using the following command:
xrandr -o right
The problem is, that after the rotation there are artifacts during the screen update. It looks like some of the screen parts are "rotated" wrongly, so I can see some elements (like parts of the matchbox panel) on a wrong location on the screen (somewhere in the middle). These artifacts are not visible via VNC (I use UltraVNC client on Windows 10), but only on the display. This lead me to a suspected bug in the vivante driver.
I can easily reproduce these artifacts by connecting to the device via VNC. When I move the mouse over the screen, artifacts (like from the original not rotated screen) start to appear immediately following the cursor on the screen.
I use the Vivante driver the same way as configured in the fsimx6sx_std_defconfig. I found on the internet, that there is a bug in Vivante with a similar description: https://community.nxp.com/thread/509185, but it looks to be for a different version of the driver.
Is there a fix or does anybody have a hint how to fix this?