I'm having an issue on the i.MX6 duallite platform.
The platform is using a modified version of 3.10.53 BSP with a FB backend.
normally, the main application that runs can get up to around a stable 30fps.
But if the screen is blanked and set back to normal again with:
$ echo 1 > /sys/class/graphics/fb0/blank
$ echo 0 > /sys/class/graphics/fb0/blank
the FPS drops dramatically to around 5 to 10 FPS and tearing is clearly visible.
The only thing I've noticed is this in dmesg:
[ 474.915254] mxc_sdc_fb fb.19: MXCFB_WAIT_FOR_VSYNC: timeout 0
The only way to get rid of these issues is restarting the main application, but then again, from the moment you blank the screen, the issues are back.
Any clues/help is much appreciated!
Apparently these exports are related:
If I disable those on the 3.10 kernel, it has no effect, tearing still visible.
If I disable them on a 3.14 kernel, the tearing is not immediately reproducible anymore.
Apparently this is a bug present in GPU driver 5.0.11p4 for 3.10.53, I suggest to update to 3.14.28 based BSP in order to upgrade the gpu driver as well. there is no gpu patch for 3.10.53 bsp. Also you can check some suggestions: Bad performance IMX6DL + Wayland + QT + OpenGLES