From 9f619d4769a22b1c2f9d8687adbbe4baae12c375 Mon Sep 17 00:00:00 2001 From: Ocean He Date: Tue, 7 Aug 2018 02:15:31 -0400 Subject: 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 Reviewed-by: Vishal Verma Signed-off-by: Dave Jiang Signed-off-by: Dan Williams --- drivers/acpi/nfit/core.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'drivers/acpi/nfit/core.c') 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; } -- cgit v1.2.3