[AGPGART] Make agp=off boot param work for Intel AGP drivers.

Signed-off-by: Dave Jones <davej@redhat.com>

drivers/char/agp/intel-agp.c

@@ -1810,6 +1810,8 @@ static struct pci_driver agp_intel_pci_driver = {
 
 static int __init agp_intel_init(void)
 {
+	if (agp_off)
+		return -EINVAL;
 	return pci_module_init(&agp_intel_pci_driver);
 }
 

drivers/char/agp/intel-mch-agp.c

@@ -622,6 +622,8 @@ static struct pci_driver agp_intelmch_pci_driver = {
 int __init agp_intelmch_init(void)
 {
 	static int agp_initialised=0;
+	if (agp_off)
+		return -EINVAL;
 
 	if (agp_initialised == 1)
 		return 0;