I set resolution of frame buffer in Intel platform using ioctl methods of Linux kernel. I able to set this resolution successfully (verify with again get this parameters) but didn't get in qt. When I check desktop geometry it was get which I set on boot (1920*1024) and also not getting resizeevent(). Can somebody say where am lacking .... ?

I also connect resize signal but it also won't work.
connect(QApplication::desktop(), SIGNAL(resized(int)), this, SLOT(resized(int)));

QDesktopWidget widget;
QRect mainScreenSize = widget.availableGeometry(widget.primaryScreen());

this also not worked. not getting any event