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authorDan Williams <dan.j.williams@intel.com>2016-07-19 21:32:39 +0200
committerDan Williams <dan.j.williams@intel.com>2016-07-19 21:32:39 +0200
commita72255983f12f31f0c8d8275fb1a781546cfacb7 (patch)
tree4c5c249460e99c8ca4e429cf0cac0ceb4018ce1b /drivers/acpi/utils.c
parentLinux 4.7-rc6 (diff)
downloadlinux-a72255983f12f31f0c8d8275fb1a781546cfacb7.tar.xz
linux-a72255983f12f31f0c8d8275fb1a781546cfacb7.zip
nfit: make DIMM DSMs optional
Commit 4995734e973a "acpi, nfit: fix acpi_check_dsm() vs zero functions implemented" attempted to fix a QEMU regression by supporting its usage of a zero-mask as a valid response to a DSM-family probe request. However, this behavior breaks HP platforms that return a zero-mask by default causing the probe to misidentify the DSM-family. Instead, the QEMU regression can be fixed by simply not requiring the DSM family to be identified. This effectively reverts commit 4995734e973a, and removes the DSM requirement from the init path. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com> Cc: Linda Knippers <linda.knippers@hpe.com> Fixes: 4995734e973a ("acpi, nfit: fix acpi_check_dsm() vs zero functions implemented") Reported-by: Jerry Hoemann <jerry.hoemann@hpe.com> Tested-by: Jerry Hoemann <jerry.hoemann@hpe.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to '')
-rw-r--r--drivers/acpi/utils.c6
1 files changed, 3 insertions, 3 deletions
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.