+ /*
+ * Apple systems with gmux are EFI based and normally don't use
+ * VGA. In addition changing IO+MEM ownership between IGP and dGPU
+ * disables IO/MEM used for backlight control on some systems.
+ * Lock IO+MEM to GPU with active IO to prevent switch.
+ */
+ pdev = gmux_get_io_pdev();
+ if (pdev && vga_tryget(pdev,
+ VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM)) {
+ pr_err("IO+MEM vgaarb-locking for PCI:%s failed\n",
+ pci_name(pdev));
+ ret = -EBUSY;
+ goto err_release;
+ } else if (pdev)
+ pr_info("locked IO for PCI:%s\n", pci_name(pdev));
+ gmux_data->pdev = pdev;
+