diff --git a/drivers/gpu/drm/mga/mga_dma.c b/drivers/gpu/drm/mga/mga_dma.c
index 1f2f9ca..4556e2b 100644
--- a/drivers/gpu/drm/mga/mga_dma.c
+++ b/drivers/gpu/drm/mga/mga_dma.c
@@ -392,6 +392,24 @@
 	drm_mga_private_t *dev_priv;
 	int ret;
 
+	/* There are PCI versions of the G450.  These cards have the
+	 * same PCI ID as the AGP G450, but have an additional PCI-to-PCI
+	 * bridge chip.  We detect these cards, which are not currently
+	 * supported by this driver, by looking at the device ID of the
+	 * bus the "card" is on.  If vendor is 0x3388 (Hint Corp) and the
+	 * device is 0x0021 (HB6 Universal PCI-PCI bridge), we reject the
+	 * device.
+	 */
+	if ((dev->pdev->device == 0x0525) && dev->pdev->bus->self
+	    && (dev->pdev->bus->self->vendor == 0x3388)
+	    && (dev->pdev->bus->self->device == 0x0021)
+	    && dev->agp) {
+		/* FIXME: This should be quirked in the pci core, but oh well
+		 * the hw probably stopped existing. */
+		arch_phys_wc_del(dev->agp->agp_mtrr);
+		kfree(dev->agp);
+		dev->agp = NULL;
+	}
 	dev_priv = kzalloc(sizeof(drm_mga_private_t), GFP_KERNEL);
 	if (!dev_priv)
 		return -ENOMEM;
@@ -698,7 +716,7 @@
 static int mga_do_dma_bootstrap(struct drm_device *dev,
 				drm_mga_dma_bootstrap_t *dma_bs)
 {
-	const int is_agp = (dma_bs->agp_mode != 0) && drm_pci_device_is_agp(dev);
+	const int is_agp = (dma_bs->agp_mode != 0) && dev->agp;
 	int err;
 	drm_mga_private_t *const dev_priv =
 	    (drm_mga_private_t *) dev->dev_private;