I'm currently working on an iMX6DL based board. We are using an HDMI display to show a Qt application.
I sometimes have a problem where the image is displayed, but there's a kind of "white veil" on it. I mean, it looks like the gamma parameter had been set to a very higher value. It stays as it is until I manually reboot the display, which I think lead to a reset of the HDMI output. When I dump the framebuffer, everything looks normal on the image I get, so I'm pretty sure that the problem does not come from the framebuffer itself.
Otherwise, I sometimes have an other problem when I run or stop a Qt app : the screen completely stops working and pixels are slowly fading to white. It looks exactly like when I blank the framebuffer, but I didnt. Also, the framebuffer / hdmi logs in dmesg don't show any framebuffer blanking. That's why I think it's most probably the HDMI that stops operating.
Do you guys have any idea of what is causing those 2 problems ?