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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-11-14 20:56:17 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-11-14 20:56:17 +0100
commite2174b0c24caca170ca61eda2ae49c9561ff8896 (patch)
tree434c1264b42d8f810b833554a6000e09cccdfeb7 /drivers/acpi
parenta25f0944ba9b1d8a6813fd6f1a86f1bd59ac25a6 (diff)
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')
-rw-r--r--drivers/acpi/acpica/tbfadt.c10
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;