2 files changed, 9 insertions, 8 deletions

diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
index ac6ddcc080d4..1f0e06065ae6 100644
--- a/drivers/acpi/nfit.c
+++ b/drivers/acpi/nfit.c
@@ -1131,11 +1131,11 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
 
         /*
          * Until standardization materializes we need to consider up to 3
-         * different command sets.  Note, that checking for zero functions
-         * tells us if any commands might be reachable through this uuid.
+         * different command sets.  Note, that checking for function0 (bit0)
+         * tells us if any commands are reachable through this uuid.
          */
         for (i = NVDIMM_FAMILY_INTEL; i <= NVDIMM_FAMILY_HPE2; i++)
-                if (acpi_check_dsm(adev_dimm->handle, to_nfit_uuid(i), 1, 0))
+                if (acpi_check_dsm(adev_dimm->handle, to_nfit_uuid(i), 1, 1))
                         break;
 
         /* limit the supported commands to those that are publicly documented */
@@ -1151,9 +1151,10 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
                 if (disable_vendor_specific)
                         dsm_mask &= ~(1 << 8);
         } else {
-                dev_err(dev, "unknown dimm command family\n");
+                dev_dbg(dev, "unknown dimm command family\n");
                 nfit_mem->family = -1;
-                return force_enable_dimms ? 0 : -ENODEV;
+                /* DSMs are optional, continue loading the driver... */
+                return 0;
         }
 
         uuid = to_nfit_uuid(nfit_mem->family);
diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index b4de130f2d57..22c09952e177 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -680,6 +680,9 @@ bool acpi_check_dsm(acpi_handle handle, const u8 *uuid, u64 rev, u64 funcs)
         u64 mask = 0;
         union acpi_object *obj;
 
+        if (funcs == 0)
+                return false;
+
         obj = acpi_evaluate_dsm(handle, uuid, rev, 0, NULL);
         if (!obj)
                 return false;
@@ -692,9 +695,6 @@ bool acpi_check_dsm(acpi_handle handle, const u8 *uuid, u64 rev, u64 funcs)
                         mask |= (((u64)obj->buffer.pointer[i]) << (i * 8));
         ACPI_FREE(obj);
 
-        if (funcs == 0)
-                return true;
-
         /*
          * Bit 0 indicates whether there's support for any functions other than
          * function 0 for the specified UUID and revision.