Added device_is_agp callback to drm_driver. This function is called by the

    platform-specific drm_device_is_agp function. Added implementation of
    this function the the Linux-specific portion of the MGA driver to
    detect PCI G450 cards. Added code to the Linux-specific portion of the
    generic DRM layer to not initialize AGP infrastructure if the card is
    not AGP (this matches what already existed in BSD).
Bumped the driver date and the driver patch-level for MGA.
This mostly fixes bugzilla #3248. The BSD side still needs an
    implementation of mga_driver_device_is_agp.

3 files changed, 62 insertions, 1 deletions

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;
+}