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| author |   Jan Engelhardt <jengelh@inai.de> | 2020-03-05 13:24:25 +0100 |
|---|---|---|
| committer |   Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2020-03-14 10:41:56 +0100 |
| commit | ecb9c790999fd6c5af0f44783bd0217f0b89ec2b (patch) | |
| tree | 3a100d2acdbba78c5e39c49649b2195ebfcf7f4b /include/acpi | |
| parent | acpi/x86: add a kernel parameter to disable ACPI BGRT (diff) | |
| download | wireguard-linux-ecb9c790999fd6c5af0f44783bd0217f0b89ec2b.tar.xz wireguard-linux-ecb9c790999fd6c5af0f44783bd0217f0b89ec2b.zip | |
acpi/x86: ignore unspecified bit positions in the ACPI global lock field
The value in "new" is constructed from "old" such that all bits defined
as reserved by the ACPI spec[1] are left untouched. But if those bits
do not happen to be all zero, "new < 3" will not evaluate to true.
The firmware of the laptop(s) Medion MD63490 / Akoya P15648 comes with
garbage inside the "FACS" ACPI table. The starting value is
old=0x4944454d, therefore new=0x4944454e, which is >= 3. Mask off
the reserved bits.
[1] https://uefi.org/sites/default/files/resources/ACPI_6_2.pdf
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206553
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'include/acpi')
0 files changed, 0 insertions, 0 deletions