https://bugs.freedesktop.org/show_bug.cgi?id=89699
--- Comment #24 from Marek Olšák maraeo@gmail.com --- We can't revert it, because it would cause other issues. Your patch is wrong, because it reverts a lot of unrelated things too.
I think the proper fix is to use the constant engine. Or upload descriptors without CP_DMA and WRITE_DATA, only using the CPU to upload them.