vga_switcheroo_register_handler
vga_switcheroo_register_handler(&amdgpu_atpx_handler, handler_flags);
vga_switcheroo_register_handler(&nouveau_dsm_handler, 0);
vga_switcheroo_register_handler(&radeon_atpx_handler, handler_flags);
EXPORT_SYMBOL(vga_switcheroo_register_handler);
ret = vga_switcheroo_register_handler(gmux_data->config->gmux_handler,
int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler,