Re: [PATCH v2] libnvdimm: re-enable deep flush for pmem devices

Re-enable deep flush so that users always have a way to be sure that a write does make it all the way out to the NVDIMM. The PMEM driver writes always make it "all the way to the NVDIMM", and it relies on the ADR mechanism to flush the write buffers on power failure. Deep flush is there to explicitly flush those write buffers to protect against (rare) ADR failure. This change prevents a regression in deep flush behavior so that applications can continue to depend on fsync() as a mechanism to trigger deep flush in the filesystem-dax case. Fixes: 06e8ccdab15f4 ("acpi: nfit: Add support for detect platform CPU cache flush on power loss") Signed-off-by: Dave Jiang <dave.jiang(a)intel.com&gt;