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| author |   Dan Williams <dan.j.williams@intel.com> | 2016-07-19 12:32:39 -0700 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2016-07-19 12:32:39 -0700 |
| commit | a72255983f12f31f0c8d8275fb1a781546cfacb7 (patch) | |
| tree | 4c5c249460e99c8ca4e429cf0cac0ceb4018ce1b /drivers/acpi/utils.c | |
| parent | Linux 4.7-rc6 (diff) | |
| download | linux-dev-a72255983f12f31f0c8d8275fb1a781546cfacb7.tar.xz linux-dev-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 'drivers/acpi/utils.c')
| -rw-r--r-- | drivers/acpi/utils.c | 6 |
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. |