1d4dd7091SDan WilliamsWhat:		/sys/bus/nd/devices/regionX/nfit/ecc_unit_size
2d4dd7091SDan WilliamsDate:		Aug, 2017
3d4dd7091SDan WilliamsKernelVersion:	v4.14 (Removed v4.18)
4d4dd7091SDan WilliamsContact:	linux-nvdimm@lists.01.org
5d4dd7091SDan WilliamsDescription:
6d4dd7091SDan Williams		(RO) Size of a write request to a DIMM that will not incur a
7d4dd7091SDan Williams		read-modify-write cycle at the memory controller.
8d4dd7091SDan Williams
9d4dd7091SDan Williams		When the nfit driver initializes it runs an ARS (Address Range
10d4dd7091SDan Williams		Scrub) operation across every pmem range. Part of that process
11d4dd7091SDan Williams		involves determining the ARS capabilities of a given address
12d4dd7091SDan Williams		range. One of the capabilities that is reported is the 'Clear
13d4dd7091SDan Williams		Uncorrectable Error Range Length Unit Size' (see: ACPI 6.2
14d4dd7091SDan Williams		section 9.20.7.4 Function Index 1 - Query ARS Capabilities).
15d4dd7091SDan Williams		This property indicates the boundary at which the NVDIMM may
16d4dd7091SDan Williams		need to perform read-modify-write cycles to maintain ECC (Error
17d4dd7091SDan Williams		Correcting Code) blocks.
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