| What: /sys/bus/nd/devices/regionX/nfit/ecc_unit_size |
| Date: Aug, 2017 |
| KernelVersion: v4.14 (Removed v4.18) |
| Contact: linux-nvdimm@lists.01.org |
| Description: |
| (RO) Size of a write request to a DIMM that will not incur a |
| read-modify-write cycle at the memory controller. |
| |
| When the nfit driver initializes it runs an ARS (Address Range |
| Scrub) operation across every pmem range. Part of that process |
| involves determining the ARS capabilities of a given address |
| range. One of the capabilities that is reported is the 'Clear |
| Uncorrectable Error Range Length Unit Size' (see: ACPI 6.2 |
| section 9.20.7.4 Function Index 1 - Query ARS Capabilities). |
| This property indicates the boundary at which the NVDIMM may |
| need to perform read-modify-write cycles to maintain ECC (Error |
| Correcting Code) blocks. |