Laptop Hybrid Graphics - GPU switching support

modulename: vga_switcheroo.ko

configname: CONFIG_VGA_SWITCHEROO

Linux Kernel Configuration
└─>Device Drivers
└─>Graphics support
└─>Laptop Hybrid Graphics - GPU switching support
In linux kernel since version 2.6.34 (release Date: 2010-05-16)  
Many laptops released in 2008/9/10 have two GPUs with a multiplexer
to switch between them. This adds support for dynamic switching when
X isn't running and delayed switching until the next logoff. This
feature is called hybrid graphics, ATI PowerXpress, and Nvidia
HybridPower.

source code: