check during play the test.avi ,the fbdev.c call the FBIOPAN_DISPLAY ???
or never call it for our sharp LCD doesnot support the Page Fliping / Double buffering ,and the xoffset or yoffset is never changed ???
about FBIOPAN_DISPLAY ioctl
It is for panning the display. Panning is when you move the image on your
screen in some direction. Panning is used by fbcon for scrolling the
It’s used to pan the screen. The argument is a fb_var_screeninfo, just like FBIOPUT_VSCREENINFO. But it looks at xoffset and yoffset only, and checks for the FB_VMODE_YWRAP flag in the vmode field.
If it’s not available, it returns -EINVAL, unless xoffset and yoffset are both 0.