0001 What: /sys/bus/nd/devices/regionX/nfit/ecc_unit_size
0002 Date: Aug, 2017
0003 KernelVersion: v4.14 (Removed v4.18)
0004 Contact: nvdimm@lists.linux.dev
0005 Description:
0006 (RO) Size of a write request to a DIMM that will not incur a
0007 read-modify-write cycle at the memory controller.
0008
0009 When the nfit driver initializes it runs an ARS (Address Range
0010 Scrub) operation across every pmem range. Part of that process
0011 involves determining the ARS capabilities of a given address
0012 range. One of the capabilities that is reported is the 'Clear
0013 Uncorrectable Error Range Length Unit Size' (see: ACPI 6.2
0014 section 9.20.7.4 Function Index 1 - Query ARS Capabilities).
0015 This property indicates the boundary at which the NVDIMM may
0016 need to perform read-modify-write cycles to maintain ECC (Error
0017 Correcting Code) blocks.
