Comment 55 for bug 1401788

Hmm, that log makes the failure path look even simpler: a single BLT copy in the batch to write into the userptr. It would be the same code path on every generation (certainly if Option "AccelMethod" "BLT" is used).

Something you can do for a quick check:

ickle@nuc-i3427:/usr/src/xf86-video-intel$ git diff
diff --git a/src/sna/kgem.c b/src/sna/kgem.c
index 66adae8..b1cf92a 100644
--- a/src/sna/kgem.c
+++ b/src/sna/kgem.c
@@ -2581,7 +2581,7 @@ bool __kgem_ring_is_idle(struct kgem *kgem, int ring)
        return true;
 }

-#if 0
+#if 1
 static void kgem_commit__check_reloc(struct kgem *kgem)
 {
        struct kgem_request *rq = kgem->next_request;

which enables the sanity check on the kernel relocation values.