From 099b07a25fff6ee1b37f3ca7f4d2b53186326db0 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 13 Jun 2018 09:06:52 -0700 Subject: [PATCH] acpi, nfit: Prefer _DSM over _LSR for namespace label reads The _LSR method indicates locked status via error-code-3 returned in the _LSR payload. When any error is returned the payload of _LSR is truncated to a zero-length buffer. The _DSM path in comparison allows system software to retrieve the locked status *and* namespace label area contents. Signed-off-by: Dan Williams --- drivers/acpi/nfit/core.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 471402cee1f1..2be8373153ed 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -1697,7 +1697,7 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc, { struct acpi_device *adev, *adev_dimm; struct device *dev = acpi_desc->dev; - unsigned long dsm_mask; + unsigned long dsm_mask, label_mask; const guid_t *guid; int i; int family = -1; @@ -1769,6 +1769,16 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc, 1ULL << i)) set_bit(i, &nfit_mem->dsm_mask); + /* + * Prefer the NVDIMM_FAMILY_INTEL label read commands if present + * due to their better semantics handling locked capacity. + */ + label_mask = 1 << ND_CMD_GET_CONFIG_SIZE | 1 << ND_CMD_GET_CONFIG_DATA + | 1 << ND_CMD_SET_CONFIG_DATA; + if (family == NVDIMM_FAMILY_INTEL + && (dsm_mask & label_mask) == label_mask) + return 0; + if (acpi_nvdimm_has_method(adev_dimm, "_LSI") && acpi_nvdimm_has_method(adev_dimm, "_LSR")) { dev_dbg(dev, "%s: has _LSR\n", dev_name(&adev_dimm->dev));