Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm fix from Dan Williams:
"This contains a regression fix for a problem that was introduced in
v4.7-rc6.
In 4.7-rc1 we introduced auto-probing for the ACPI DSM (device-
specific-method) format that the platform firmware implements for
nvdimm devices. We initially fixed a regression in probing the QEMU
DSM implementation by making acpi_check_dsm() tolerant of the way QEMU
reports the "0 DSMs supported" condition.
However, that broke HPE platforms since that tolerance caused the
driver to mistakenly match the 1-zero-byte response those platforms
give to "unknown" commands. Instead, we simply make the driver
tolerant of not finding any supported DSMs. This has been tested to
work with both QEMU and HPE platforms.
This commit has appeared in a -next release with no reported issues"
* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
nfit: make DIMM DSMs optional
diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
index ac6ddcc0..1f0e060 100644
--- a/drivers/acpi/nfit.c
+++ b/drivers/acpi/nfit.c
@@ -1131,11 +1131,11 @@
/*
* 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 @@
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 b4de130..22c0995 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -680,6 +680,9 @@
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 @@
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.
