1 files changed, 31 insertions, 0 deletions

diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index d412a1ddc12f..f8a09bf8d0cd 100644
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -1462,6 +1462,16 @@ static int fb_check_foreignness(struct fb_info *fi)
         return 0;
 }
 
+static bool fb_do_apertures_overlap(struct fb_info *gen, struct fb_info *hw)
+{
+        /* is the generic aperture base the same as the HW one */
+        if (gen->aperture_base == hw->aperture_base)
+                return true;
+        /* is the generic aperture base inside the hw base->hw base+size */
+        if (gen->aperture_base > hw->aperture_base && gen->aperture_base <= hw->aperture_base + hw->aperture_size)
+                return true;
+        return false;
+}
 /**
  *      register_framebuffer - registers a frame buffer device
  *      @fb_info: frame buffer info structure
@@ -1485,6 +1495,23 @@ register_framebuffer(struct fb_info *fb_info)
         if (fb_check_foreignness(fb_info))
                 return -ENOSYS;
 
+        /* check all firmware fbs and kick off if the base addr overlaps */
+        for (i = 0 ; i < FB_MAX; i++) {
+                if (!registered_fb[i])
+                        continue;
+
+                if (registered_fb[i]->flags & FBINFO_MISC_FIRMWARE) {
+                        if (fb_do_apertures_overlap(registered_fb[i], fb_info)) {
+                                printk(KERN_ERR "fb: conflicting fb hw usage "
+                                       "%s vs %s - removing generic driver\n",
+                                       fb_info->fix.id,
+                                       registered_fb[i]->fix.id);
+                                unregister_framebuffer(registered_fb[i]);
+                                break;
+                        }
+                }
+        }
+
         num_registered_fb++;
         for (i = 0 ; i < FB_MAX; i++)
                 if (!registered_fb[i])
@@ -1586,6 +1613,10 @@ unregister_framebuffer(struct fb_info *fb_info)
         device_destroy(fb_class, MKDEV(FB_MAJOR, i));
         event.info = fb_info;
         fb_notifier_call_chain(FB_EVENT_FB_UNREGISTERED, &event);
+
+        /* this may free fb info */
+        if (fb_info->fbops->fb_destroy)
+                fb_info->fbops->fb_destroy(fb_info);
 done:
         return ret;
 }