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author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-11-14 20:56:17 +0100 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-11-14 20:56:17 +0100 |
commit | e2174b0c24caca170ca61eda2ae49c9561ff8896 (patch) | |
tree | 434c1264b42d8f810b833554a6000e09cccdfeb7 /drivers/acpi/acpica/tbfadt.c | |
parent | Linux 4.9-rc5 (diff) | |
download | linux-e2174b0c24caca170ca61eda2ae49c9561ff8896.tar.xz linux-e2174b0c24caca170ca61eda2ae49c9561ff8896.zip |
Revert "ACPICA: FADT support cleanup"
Pavel Machek reports that commit 6ea8c546f365 (ACPICA: FADT support
cleanup) breaks thermal management on his Thinkpad X60 and T40p, so
revert it.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=187311
Fixes: 6ea8c546f365 (ACPICA: FADT support cleanup)
Reported-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/acpica/tbfadt.c')
-rw-r--r-- | drivers/acpi/acpica/tbfadt.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/drivers/acpi/acpica/tbfadt.c b/drivers/acpi/acpica/tbfadt.c index 046c4d0394ee..5fb838e592dc 100644 --- a/drivers/acpi/acpica/tbfadt.c +++ b/drivers/acpi/acpica/tbfadt.c @@ -480,19 +480,17 @@ static void acpi_tb_convert_fadt(void) u32 i; /* - * For ACPI 1.0 FADTs (revision 1), ensure that reserved fields which + * For ACPI 1.0 FADTs (revision 1 or 2), ensure that reserved fields which * should be zero are indeed zero. This will workaround BIOSs that * inadvertently place values in these fields. * * The ACPI 1.0 reserved fields that will be zeroed are the bytes located * at offset 45, 55, 95, and the word located at offset 109, 110. * - * Note: The FADT revision value is unreliable because of BIOS errors. - * The table length is instead used as the final word on the version. - * - * Note: FADT revision 3 is the ACPI 2.0 version of the FADT. + * Note: The FADT revision value is unreliable. Only the length can be + * trusted. */ - if (acpi_gbl_FADT.header.length <= ACPI_FADT_V3_SIZE) { + if (acpi_gbl_FADT.header.length <= ACPI_FADT_V2_SIZE) { acpi_gbl_FADT.preferred_profile = 0; acpi_gbl_FADT.pstate_control = 0; acpi_gbl_FADT.cst_control = 0; |