Commit e2174b0c authored by Rafael J. Wysocki's avatar Rafael J. Wysocki

Revert "ACPICA: FADT support cleanup"

Pavel Machek reports that commit 6ea8c546 (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: 6ea8c546 (ACPICA: FADT support cleanup)
Reported-by: default avatarPavel Machek <pavel@ucw.cz>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent a25f0944
...@@ -480,19 +480,17 @@ static void acpi_tb_convert_fadt(void) ...@@ -480,19 +480,17 @@ static void acpi_tb_convert_fadt(void)
u32 i; 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 * should be zero are indeed zero. This will workaround BIOSs that
* inadvertently place values in these fields. * inadvertently place values in these fields.
* *
* The ACPI 1.0 reserved fields that will be zeroed are the bytes located * 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. * at offset 45, 55, 95, and the word located at offset 109, 110.
* *
* Note: The FADT revision value is unreliable because of BIOS errors. * Note: The FADT revision value is unreliable. Only the length can be
* The table length is instead used as the final word on the version. * trusted.
*
* Note: FADT revision 3 is the ACPI 2.0 version of the FADT.
*/ */
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.preferred_profile = 0;
acpi_gbl_FADT.pstate_control = 0; acpi_gbl_FADT.pstate_control = 0;
acpi_gbl_FADT.cst_control = 0; acpi_gbl_FADT.cst_control = 0;
......
This diff is collapsed.
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment