1 files changed, 9 insertions, 8 deletions

diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c
index 3e257a50bf56..61e1ef90d4e5 100644
--- a/drivers/gpu/drm/drm_bufs.c
+++ b/drivers/gpu/drm/drm_bufs.c
@@ -46,10 +46,11 @@ static struct drm_map_list *drm_find_matching_map(struct drm_device *dev,
         list_for_each_entry(entry, &dev->maplist, head) {
                 /*
                  * Because the kernel-userspace ABI is fixed at a 32-bit offset
-                 * while PCI resources may live above that, we ignore the map
-                 * offset for maps of type _DRM_FRAMEBUFFER or _DRM_REGISTERS.
-                 * It is assumed that each driver will have only one resource of
-                 * each type.
+                 * while PCI resources may live above that, we only compare the
+                 * lower 32 bits of the map offset for maps of type
+                 * _DRM_FRAMEBUFFER or _DRM_REGISTERS.
+                 * It is assumed that if a driver have more than one resource
+                 * of each type, the lower 32 bits are different.
                  */
                 if (!entry->map ||
                     map->type != entry->map->type ||
@@ -59,9 +60,12 @@ static struct drm_map_list *drm_find_matching_map(struct drm_device *dev,
                 case _DRM_SHM:
                         if (map->flags != _DRM_CONTAINS_LOCK)
                                 break;
+                        return entry;
                 case _DRM_REGISTERS:
                 case _DRM_FRAME_BUFFER:
-                        return entry;
+                        if ((entry->map->offset & 0xffffffff) ==
+                            (map->offset & 0xffffffff))
+                                return entry;
                 default: /* Make gcc happy */
                         ;
                 }
@@ -183,9 +187,6 @@ static int drm_addmap_core(struct drm_device * dev, resource_size_t offset,
                         return -EINVAL;
                 }
 #endif
-#ifdef __alpha__
-                map->offset += dev->hose->mem_space->start;
-#endif
                 /* Some drivers preinitialize some maps, without the X Server
                  * needing to be aware of it.  Therefore, we just return success
                  * when the server tries to create a duplicate map.