diff --git a/kernel/file_ops.c b/kernel/file_ops.c
index 96510492..c02cadc9 100644
--- a/kernel/file_ops.c
+++ b/kernel/file_ops.c
@@ -516,18 +516,9 @@ long hfi1_file_ioctl(void *private_data, unsigned int cmd,
 
 	case HFI1_IOCTL_TID_INVAL_READ:
 		kprintf("%s: HFI1_IOCTL_TID_INVAL_READ \n", __FUNCTION__);
-		if (copy_from_user(&tinfo,
-				   (struct hfi11_tid_info __user *)arg,
-				   sizeof(tinfo)))
-			return -EFAULT;
-
-		ret = hfi1_user_exp_rcv_invalid(fd, &tinfo);
-		if (ret)
-			break;
-		addr = arg + offsetof(struct hfi1_tid_info, tidcnt);
-		if (copy_to_user((void __user *)addr, &tinfo.tidcnt,
-				 sizeof(tinfo.tidcnt)))
-			ret = -EFAULT;
+		/* This function is only invovled with the tid mmu caching.
+		 * It is a no-op for us. */
+		ret = 0;
 		break;
 
 	case HFI1_IOCTL_RECV_CTRL:
diff --git a/kernel/user_exp_rcv.c b/kernel/user_exp_rcv.c
index 9a265b97..de7bd774 100644
--- a/kernel/user_exp_rcv.c
+++ b/kernel/user_exp_rcv.c
@@ -256,58 +256,6 @@ done:
 	return ret;
 }
 
-int hfi1_user_exp_rcv_invalid(struct hfi1_filedata *fd, struct hfi1_tid_info *tinfo)
-{
-#if 0
-	struct hfi1_ctxtdata *uctxt = fd->uctxt;
-	unsigned long *ev = uctxt->dd->events +
-		(((uctxt->ctxt - uctxt->dd->first_user_ctxt) *
-		  HFI1_MAX_SHARED_CTXTS) + fd->subctxt);
-	u32 *array;
-	int ret = 0;
-
-	if (!fd->invalid_tids)
-		return -EINVAL;
-
-	/*
-	 * copy_to_user() can sleep, which will leave the invalid_lock
-	 * locked and cause the MMU notifier to be blocked on the lock
-	 * for a long time.
-	 * Copy the data to a local buffer so we can release the lock.
-	 */
-	array = kcalloc(uctxt->expected_count, sizeof(*array), GFP_KERNEL);
-	if (!array)
-		return -EFAULT;
-
-	spin_lock(&fd->invalid_lock);
-	if (fd->invalid_tid_idx) {
-		memcpy(array, fd->invalid_tids, sizeof(*array) *
-		       fd->invalid_tid_idx);
-		memset(fd->invalid_tids, 0, sizeof(*fd->invalid_tids) *
-		       fd->invalid_tid_idx);
-		tinfo->tidcnt = fd->invalid_tid_idx;
-		fd->invalid_tid_idx = 0;
-		/*
-		 * Reset the user flag while still holding the lock.
-		 * Otherwise, PSM can miss events.
-		 */
-		clear_bit(_HFI1_EVENT_TID_MMU_NOTIFY_BIT, ev);
-	} else {
-		tinfo->tidcnt = 0;
-	}
-	spin_unlock(&fd->invalid_lock);
-
-	if (tinfo->tidcnt) {
-		if (copy_to_user((void __user *)tinfo->tidlist,
-				 array, sizeof(*array) * tinfo->tidcnt))
-			ret = -EFAULT;
-	}
-	kfree(array);
-
-	return ret;
-#endif
-	return 0;
-}
 /**
  * program_rcvarray() - program an RcvArray group with receive buffers
  * @fd: file data