Modify drm_driver::device_is_agp to return a tri-state value to indicate

    that a device absolutely is, absolutely is not, or may or may not be
    AGP. Modify the i915 DRM to use this to force all i9x5 devices to be
    "AGP" (even the PCI-e devices).
Reported by: Lukas Hejtmanek

1 files changed, 10 insertions, 5 deletions

diff --git a/linux-core/drmP.h b/linux-core/drmP.h
index 167bef0f..24d8a23b 100644
--- a/linux-core/drmP.h
+++ b/linux-core/drmP.h
@@ -548,8 +548,10 @@ struct drm_driver {
 	 *
 	 * \param dev  DRM device handle
 	 *
-	 * \returns true if the card really is attached to AGP, false
-	 * otherwise.
+	 * \returns
+	 * One of three values is returned depending on whether or not the
+	 * card is absolutely \b not AGP (return of 0), absolutely \b is AGP
+	 * (return of 1), or may or may not be AGP (return of 2).
 	 */
 	int (*device_is_agp) (struct drm_device * dev);
 
@@ -1028,9 +1030,12 @@ 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;
+	if ( dev->driver->device_is_agp != NULL ) {
+		int err = (*dev->driver->device_is_agp)( dev );
+	
+		if (err != 2) {
+			return err;
+		}
 	}
 
 	return pci_find_capability(dev->pdev, PCI_CAP_ID_AGP);