git: acpi/pstate: Allow missing _PCT and _PSS, as long as _PSD exists

Sepherosa Ziehau sephe at
Wed Jan 14 17:04:00 PST 2015

commit 6ac1e346bb30cf49c6459109028e98c17b3b167c
Author: Sepherosa Ziehau <sephe at>
Date:   Wed Jan 14 20:14:07 2015 +0800

    acpi/pstate: Allow missing _PCT and _PSS, as long as _PSD exists
    Some BIOSes does not export _PCT and _PSS for the second thread of CPU
    cores.  As long as _PSD exists and control/status registers are "fixed
    hardware", e.g. for most of the modern Intel CPUs, we could reconstruct
    P-state for the CPU even if there are no _PCT or _PSS.
    In case that _PSD is wrong, e.g. 2 threads of a same core are in different
    P-state domain, we try to put them to the same P-state domain.  This could
    be disabled by setting tunable hw.acpi.cpu.pst.ht_reuse_domain to 0; this
    tunable is 1 by default.

Summary of changes:
 sys/dev/acpica/acpi_cpu_pstate.c | 143 ++++++++++++++++++++++++++++++++++-----
 1 file changed, 125 insertions(+), 18 deletions(-)

DragonFly BSD source repository

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