AST_MAX_HWC_HEIGHT
if (new_fb->width > AST_MAX_HWC_WIDTH || new_fb->height > AST_MAX_HWC_HEIGHT)
offset_y = AST_MAX_HWC_HEIGHT - fb->height;
#define AST_HWC_SIZE (AST_MAX_HWC_HEIGHT * AST_HWC_PITCH)