1 files changed, 9 insertions, 2 deletions

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 6bc784bd0828..98d3bc6b90f1 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -55,6 +55,11 @@ static unsigned long override_dsm_mask;
 module_param(override_dsm_mask, ulong, S_IRUGO);
 MODULE_PARM_DESC(override_dsm_mask, "Bitmask of allowed NVDIMM DSM functions");
 
+static int default_dsm_family = -1;
+module_param(default_dsm_family, int, S_IRUGO);
+MODULE_PARM_DESC(default_dsm_family,
+                "Try this DSM type first when identifying NVDIMM family");
+
 LIST_HEAD(acpi_descs);
 DEFINE_MUTEX(acpi_desc_lock);
 
@@ -1372,6 +1377,7 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
         unsigned long dsm_mask;
         const u8 *uuid;
         int i;
+        int family = -1;
 
         /* nfit test assumes 1:1 relationship between commands and dsms */
         nfit_mem->dsm_mask = acpi_desc->dimm_cmd_force_en;
@@ -1402,10 +1408,11 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
          */
         for (i = NVDIMM_FAMILY_INTEL; i <= NVDIMM_FAMILY_MSFT; i++)
                 if (acpi_check_dsm(adev_dimm->handle, to_nfit_uuid(i), 1, 1))
-                        break;
+                        if (family < 0 || i == default_dsm_family)
+                                family = i;
 
         /* limit the supported commands to those that are publicly documented */
-        nfit_mem->family = i;
+        nfit_mem->family = family;
         if (override_dsm_mask && !disable_vendor_specific)
                 dsm_mask = override_dsm_mask;
         else if (nfit_mem->family == NVDIMM_FAMILY_INTEL) {