acpi_video: Intel video is not always i915

Stop it poking at random registers on the i740 cards that may be out there
still.

As per Matthew's feedback remove the conditional checks and never enable the
opregion handling unless an appropriate driver has been loaded.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

drivers/acpi/video.c

@@ -1743,10 +1743,18 @@ static int acpi_video_bus_remove(struct acpi_device *device, int type)
 	return 0;
 }
 
+static int __init is_i740(struct pci_dev *dev)
+{
+	if (dev->device == 0x00D1)
+		return 1;
+	if (dev->device == 0x7000)
+		return 1;
+	return 0;
+}
+
 static int __init intel_opregion_present(void)
 {
-	int i915 = 0;
-#if defined(CONFIG_DRM_I915) || defined(CONFIG_DRM_I915_MODULE)
+	int opregion = 0;
 	struct pci_dev *dev = NULL;
 	u32 address;
 
@@ -1755,13 +1763,15 @@ static int __init intel_opregion_present(void)
 			continue;
 		if (dev->vendor != PCI_VENDOR_ID_INTEL)
 			continue;
+		/* We don't want to poke around undefined i740 registers */
+		if (is_i740(dev))
+			continue;
 		pci_read_config_dword(dev, 0xfc, &address);
 		if (!address)
 			continue;
-		i915 = 1;
+		opregion = 1;
 	}
-#endif
-	return i915;
+	return opregion;
 }
 
 int acpi_video_register(void)