[PATCH 4.14 070/125] acpi-cpufreq: Honor _PSD table setting on new AMD CPUs

Greg Kroah-Hartman
2020-11-03T21:12:54Z

From: Wei Huang <wei.huang2@amd.com>

commit 5368512abe08a28525d9b24abbfc2a72493e8dba upstream.

acpi-cpufreq has a old quirk that overrides the _PSD table supplied by
BIOS on AMD CPUs. However the _PSD table of new AMD CPUs (Family 19h+)
now accurately reports the P-state dependency of CPU cores. Hence this
quirk needs to be fixed in order to support new CPUs' frequency control.

Fixes: acd316248205 ("acpi-cpufreq: Add quirk to disable _PSD usage on all AMD CPUs")
Signed-off-by: Wei Huang <wei.huang2@amd.com>
[ rjw: Subject edit ]
Cc: 3.10+ <stable@vger.kernel.org> # 3.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/cpufreq/acpi-cpufreq.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -701,7 +701,8 @@ static int acpi_cpufreq_cpu_init(struct
cpumask_copy(policy->cpus, topology_core_cpumask(cpu));
}

- if (check_amd_hwpstate_cpu(cpu) && !acpi_pstate_strict) {
+ if (check_amd_hwpstate_cpu(cpu) && boot_cpu_data.x86 < 0x19 &&
+ !acpi_pstate_strict) {
cpumask_clear(policy->cpus);
cpumask_set_cpu(cpu, policy->cpus);
cpumask_copy(data->freqdomain_cpus,