we are using i.MX6 #imx6 dualplus/6quadplus Custom Board.
In that we are observing little flickering once booting up. after pSplash Screen comes,
when debugged we have observed various observation,
Below are the Observations.
Ob 1 : while debugging "/etc/init.d/xserver-nodm" in this script file X11 server is starting >>>>>>>> echo "Starting Xserver" >>>>>>>> . /etc/X11/xserver-common >>>>>>>> xinit /etc/X11/Xsession -- `which $XSERVER` $ARGS >/var/log/Xsession.log 2>&1 after commenting above script board boots completely without any flickering but not moving from psplash screen to Yocto desktop after that once enabled, Psplash screen goes then LCD flickers start for 2 - 4 seconds then going to Yocto Linux Home page. #splash_screen
Ob2 : Further debugging in X11 folder under the linux file system we got know one script called "/etc/X11/xorg.conf" in this script #xserver-xorg-video-imx-viv
Identifier "i.MX Accelerated Framebuffer Device"
Option "fbdev" "/dev/fb0"
Option "vivante_fbdev" "/dev/fb0"
Option "HWcursor" "false"
Option "mode_settings" "false"
Option "BlankTime" "0"
Option "StandbyTime" "0"
Option "SuspendTime" "0"
Option "OffTime" "0"
>>>>>> however mode_settings in false but still why X11 starts flickering
Ob 3 : After exploring into in-depth we have got some answered query from
NXP community below are the link,
in above link same observation has got to one user also they have solved but unfortunately they are using Old Yocto kernel.
I am not sure if it is an issue, it is not actually a flicker it is the transition from the splash screen -> terminal -> window manager. I just checked my 5.4.24 bsp on qxp board running xwayland and I see the same behavior, but it is faster.