Comment # 29 on bug 72685 from Marek Olšák

> 2) In-place DB flushing is broken with HTILE. The DB->CB copy can be used
> instead.

The flushing didn't work because of incorrect macrotile bank rotation of
non-zero slices. Sanctuary works fine with the first workaround and added bank
rotation, so we're close to closing this bug.