diff --git a/bsd-core/drmP.h b/bsd-core/drmP.h
index 6af29718..9943a4f6 100644
--- a/bsd-core/drmP.h
+++ b/bsd-core/drmP.h
@@ -638,6 +638,18 @@ struct drm_device {
 	void	(*irq_handler)(DRM_IRQ_ARGS);
 	int	(*vblank_wait)(drm_device_t *dev, unsigned int *sequence);
 
+	/**
+	 * Called by \c drm_device_is_agp.  Typically used to determine if a
+	 * card is really attached to AGP or not.
+	 *
+	 * \param dev  DRM device handle
+	 *
+	 * \returns true if the card really is attached to AGP, false
+	 * otherwise.
+	 */
+	int (*device_is_agp) (struct drm_device * dev);
+
+
 	drm_ioctl_desc_t *driver_ioctls;
 	int	max_driver_ioctl;
 
diff --git a/bsd-core/drm_agpsupport.c b/bsd-core/drm_agpsupport.c
index 6d58134a..33fb3f0c 100644
--- a/bsd-core/drm_agpsupport.c
+++ b/bsd-core/drm_agpsupport.c
@@ -46,6 +46,12 @@ drm_device_is_agp(drm_device_t *dev)
 	u_int32_t status;
 	u_int8_t ptr, next;
 
+
+	if ( (dev->driver->device_is_agp != NULL)
+	     && ! (*dev->driver->device_is_agp)( dev ) ) {
+		return 0;
+	}
+
 	/*
 	 * Check the CAP_LIST bit of the PCI status register first.
 	 */
@@ -71,6 +77,11 @@ drm_device_is_agp(drm_device_t *dev)
 
 	return 0;
 #else
+	if ( (dev->driver->device_is_agp != NULL)
+	     && ! (*dev->driver->device_is_agp)( dev ) ) {
+		return 0;
+	}
+
 	/* XXX: fill me in for non-FreeBSD */
 	return 1;
 #endif
diff --git a/bsd-core/mga_drv.c b/bsd-core/mga_drv.c
index bff8c42f..1dd4c81b 100644
--- a/bsd-core/mga_drv.c
+++ b/bsd-core/mga_drv.c
@@ -37,11 +37,14 @@
 #include "mga_drv.h"
 #include "drm_pciids.h"
 
+int mga_driver_device_is_agp(drm_device_t * dev)
 /* drv_PCI_IDs comes from drm_pciids.h, generated from drm_pciids.txt. */
 static drm_pci_id_list_t mga_pciidlist[] = {
 	mga_PCI_IDS
 };
 
+static int mga_driver_device_is_agp(drm_device_t * dev);
+
 extern drm_ioctl_desc_t mga_ioctls[];
 extern int mga_max_ioctl;
 
@@ -58,6 +61,8 @@ static void mga_configure(drm_device_t *dev)
 	dev->dma_ioctl = mga_dma_buffers;
 	dev->dma_quiescent = mga_driver_dma_quiescent;
 
+	dev->device_is_agp = mga_driver_device_is_agp;
+
 	dev->driver_ioctls = mga_ioctls;
 	dev->max_driver_ioctl = mga_max_ioctl;
 
@@ -76,6 +81,28 @@ static void mga_configure(drm_device_t *dev)
 	dev->use_vbl_irq = 1;
 }
 
+/**
+ * Determine if the device really is AGP or not.
+ *
+ * In addition to the usual tests performed by \c drm_device_is_agp, this
+ * function detects PCI G450 cards that appear to the system exactly like
+ * AGP G450 cards.
+ *
+ * \param dev   The device to be tested.
+ *
+ * \returns
+ * If the device is a PCI G450, zero is returned.  Otherwise non-zero is
+ * returned.
+ *
+ * \bug
+ * This function needs to be filled in!  The implementation in
+ * linux-core/mga_drv.c shows what needs to be done.
+ */
+int mga_driver_device_is_agp(drm_device_t * dev)
+{
+	return 1;
+}
+
 #ifdef __FreeBSD__
 static int
 mga_probe(device_t dev)
diff --git a/linux-core/drmP.h b/linux-core/drmP.h
index b7f4640f..167bef0f 100644
--- a/linux-core/drmP.h
+++ b/linux-core/drmP.h
@@ -541,6 +541,18 @@ struct drm_driver {
 				      int new);
 	int (*kernel_context_switch_unlock) (struct drm_device * dev);
 	int (*vblank_wait) (struct drm_device * dev, unsigned int *sequence);
+
+	/**
+	 * Called by \c drm_device_is_agp.  Typically used to determine if a
+	 * card is really attached to AGP or not.
+	 *
+	 * \param dev  DRM device handle
+	 *
+	 * \returns true if the card really is attached to AGP, false
+	 * otherwise.
+	 */
+	int (*device_is_agp) (struct drm_device * dev);
+
 /* these have to be filled in */
 	int (*postinit) (struct drm_device *, unsigned long flags);
 	 irqreturn_t(*irq_handler) (DRM_IRQ_ARGS);
@@ -1016,6 +1028,11 @@ static __inline__ struct drm_map *drm_core_findmap(struct drm_device *dev,
 
 static __inline__ int drm_device_is_agp(drm_device_t *dev)
 {
+	if ( (dev->driver->device_is_agp != NULL)
+	     && ! (*dev->driver->device_is_agp)( dev ) ) {
+		return 0;
+	}
+
 	return pci_find_capability(dev->pdev, PCI_CAP_ID_AGP);
 }
 
diff --git a/linux-core/drm_stub.c b/linux-core/drm_stub.c
index a3cc5667..338996d6 100644
--- a/linux-core/drm_stub.c
+++ b/linux-core/drm_stub.c
@@ -99,7 +99,8 @@ static int fill_in_dev(drm_device_t * dev, struct pci_dev *pdev,
 			goto error_out_unreg;
 
 	if (drm_core_has_AGP(dev)) {
-		dev->agp = drm_agp_init(dev);
+		if (drm_device_is_agp(dev))
+			dev->agp = drm_agp_init(dev);
 		if (drm_core_check_feature(dev, DRIVER_REQUIRE_AGP)
 		    && (dev->agp == NULL)) {
 			DRM_ERROR("Cannot initialize the agpgart module.\n");
diff --git a/linux-core/mga_drv.c b/linux-core/mga_drv.c
index bdb591ee..e0f1ab31 100644
--- a/linux-core/mga_drv.c
+++ b/linux-core/mga_drv.c
@@ -37,6 +37,7 @@
 
 #include "drm_pciids.h"
 
+static int mga_driver_device_is_agp(drm_device_t * dev);
 static int postinit(struct drm_device *dev, unsigned long flags)
 {
 	dev->counters += 3;
@@ -82,6 +83,7 @@ static struct drm_driver driver = {
 	    DRIVER_IRQ_VBL,
 	.pretakedown = mga_driver_pretakedown,
 	.dma_quiescent = mga_driver_dma_quiescent,
+	.device_is_agp = mga_driver_device_is_agp,
 	.vblank_wait = mga_driver_vblank_wait,
 	.irq_preinstall = mga_driver_irq_preinstall,
 	.irq_postinstall = mga_driver_irq_postinstall,
@@ -134,3 +136,44 @@ module_exit(mga_exit);
 MODULE_AUTHOR(DRIVER_AUTHOR);
 MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_LICENSE("GPL and additional rights");
+
+/**
+ * Determine if the device really is AGP or not.
+ *
+ * In addition to the usual tests performed by \c drm_device_is_agp, this
+ * function detects PCI G450 cards that appear to the system exactly like
+ * AGP G450 cards.
+ *
+ * \param dev   The device to be tested.
+ *
+ * \returns
+ * If the device is a PCI G450, zero is returned.  Otherwise non-zero is
+ * returned.
+ */
+int mga_driver_device_is_agp(drm_device_t * dev)
+{
+	const struct pci_dev * const pdev = dev->pdev;
+
+
+	/* 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 ( (pdev->device == 0x0525)
+	     && (pdev->bus->self->vendor == 0x3388)
+	     && (pdev->bus->self->device == 0x0021) ) {
+#if defined( __powerpc__ )
+		DRM_ERROR("GXT135p is not yet supported\n");
+#else
+		DRM_ERROR("PCI G450 is not yet supported\n");
+#endif
+		return 0;
+	}
+
+	return 1;
+}
diff --git a/shared-core/mga_drv.h b/shared-core/mga_drv.h
index 55d3f85c..f1c3cf3e 100644
--- a/shared-core/mga_drv.h
+++ b/shared-core/mga_drv.h
@@ -38,11 +38,11 @@
 
 #define DRIVER_NAME		"mga"
 #define DRIVER_DESC		"Matrox G200/G400"
-#define DRIVER_DATE		"20021029"
+#define DRIVER_DATE		"20051013"
 
 #define DRIVER_MAJOR		3
 #define DRIVER_MINOR		1
-#define DRIVER_PATCHLEVEL	0
+#define DRIVER_PATCHLEVEL	1
 
 typedef struct drm_mga_primary_buffer {
 	u8 *start;