PCI/VGA: Select VGA devices earlier

Select VGA devices in vga_arb_device_init() and pci_notify() instead of in
vga_arbiter_add_pci_device().

This is a trivial optimization for adding devices. It's a bigger
optimization for the removal case because pci_notify() won't call
vga_arbiter_del_pci_device() for non-VGA devices, so it won't have to
search the vga_list for them.

https://lore.kernel.org/r/[e-mail]
Signed-off-by: Sui Jingfeng <[e-mail]>
[bhelgaas: commit log, split from functional change]
Signed-off-by: Bjorn Helgaas <[e-mail]>

drivers/pci/vgaarb.c

···
 	struct pci_dev *bridge;
 	u16 cmd;
 
-	/* Only deal with VGA class devices */
-	if (!pci_is_vga(pdev))
-		return false;
-
 	/* Allocate structure */
 	vgadev = kzalloc(sizeof(struct vga_device), GFP_KERNEL);
 	if (vgadev == NULL) {
···
 
 	vgaarb_dbg(dev, "%s\n", __func__);
 
+	/* Only deal with VGA class devices */
+	if (!pci_is_vga(pdev))
+		return 0;
+
 	/*
 	 * For now, we're only interested in devices added and removed.
 	 * I didn't test this thing here, so someone needs to double check
···
 	pdev = NULL;
 	while ((pdev =
 		pci_get_subsys(PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID,
-			       PCI_ANY_ID, pdev)) != NULL)
-		vga_arbiter_add_pci_device(pdev);
+			       PCI_ANY_ID, pdev)) != NULL) {
+		if (pci_is_vga(pdev))
+			vga_arbiter_add_pci_device(pdev);
+	}
 
 	pr_info("loaded\n");
 	return rc;