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authorOcean He <hehy1@lenovo.com>2018-08-07 02:15:31 -0400
committerDan Williams <dan.j.williams@intel.com>2018-12-10 15:41:50 -0800
commit9f619d4769a22b1c2f9d8687adbbe4baae12c375 (patch)
treedb66e1ee32ba5f436d3ff4ba7d4542514bca62de /drivers/acpi/nfit/core.c
parent9bf3aa44644721b287724ecac835d38f1dae4e2d (diff)
ACPI/nfit: Adjust annotation for why return 0 if fail to find NFIT at start
Add detailed explanation for why it's ok to return 0 if we fail to find an NFIT at startup. Refer to chapter 9.20.2 NVDIMM Root Device in ACPI 6.2 spec. Signed-off-by: Ocean He <hehy1@lenovo.com> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/acpi/nfit/core.c')
-rw-r--r--drivers/acpi/nfit/core.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 5912d30020c7..59dd07c94f12 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -3474,7 +3474,13 @@ static int acpi_nfit_add(struct acpi_device *adev)
status = acpi_get_table(ACPI_SIG_NFIT, 0, &tbl);
if (ACPI_FAILURE(status)) {
- /* This is ok, we could have an nvdimm hotplugged later */
+ /* The NVDIMM root device allows OS to trigger enumeration of
+ * NVDIMMs through NFIT at boot time and re-enumeration at
+ * root level via the _FIT method during runtime.
+ * This is ok to return 0 here, we could have an nvdimm
+ * hotplugged later and evaluate _FIT method which returns
+ * data in the format of a series of NFIT Structures.
+ */
dev_dbg(dev, "failed to find NFIT at startup\n");
return 0;
}