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 <[email protected]>
---
drivers/cpufreq/acpi-cpufreq.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
index e4ff681faaaa..1e6e2abde428 100644
--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -691,7 +691,8 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
cpumask_copy(policy->cpus, topology_core_cpumask(cpu));
}
- if (check_amd_hwpstate_cpu(cpu) && !acpi_pstate_strict) {
+ if (check_amd_hwpstate_cpu(cpu) && (c->x86 < 0x19) &&
+ !acpi_pstate_strict) {
cpumask_clear(policy->cpus);
cpumask_set_cpu(cpu, policy->cpus);
cpumask_copy(data->freqdomain_cpus,
--
2.26.2
On Wed, Oct 7, 2020 at 10:44 PM Wei Huang <[email protected]> wrote:
>
> 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 <[email protected]>
> ---
> drivers/cpufreq/acpi-cpufreq.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
> index e4ff681faaaa..1e6e2abde428 100644
> --- a/drivers/cpufreq/acpi-cpufreq.c
> +++ b/drivers/cpufreq/acpi-cpufreq.c
> @@ -691,7 +691,8 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
> cpumask_copy(policy->cpus, topology_core_cpumask(cpu));
> }
>
> - if (check_amd_hwpstate_cpu(cpu) && !acpi_pstate_strict) {
> + if (check_amd_hwpstate_cpu(cpu) && (c->x86 < 0x19) &&
Why don't you use boot_cpu_data instead of *c?
And why don't you do the extra check in check_amd_hwpstate_cpu()?
Also the parens around it are not necessary here and is there any
chance for having a proper symbol instead of the raw 0x19 in that
check?
> + !acpi_pstate_strict) {
> cpumask_clear(policy->cpus);
> cpumask_set_cpu(cpu, policy->cpus);
> cpumask_copy(data->freqdomain_cpus,
> --
> 2.26.2
>
On 10/16 04:58, Rafael J. Wysocki wrote:
> On Wed, Oct 7, 2020 at 10:44 PM Wei Huang <[email protected]> wrote:
> >
> > 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 <[email protected]>
> > ---
> > drivers/cpufreq/acpi-cpufreq.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
> > index e4ff681faaaa..1e6e2abde428 100644
> > --- a/drivers/cpufreq/acpi-cpufreq.c
> > +++ b/drivers/cpufreq/acpi-cpufreq.c
> > @@ -691,7 +691,8 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
> > cpumask_copy(policy->cpus, topology_core_cpumask(cpu));
> > }
> >
> > - if (check_amd_hwpstate_cpu(cpu) && !acpi_pstate_strict) {
> > + if (check_amd_hwpstate_cpu(cpu) && (c->x86 < 0x19) &&
>
> Why don't you use boot_cpu_data instead of *c?
Thanks for your review. c->x86 contains the same level of information as boot_cpu_data when
acpi_cpufreq_cpu_init() starts to execute. But you are right, it is better to use boot_cpu_data,
consistent with the rest code in the same function.
>
> And why don't you do the extra check in check_amd_hwpstate_cpu()?
check_amd_hwpstate_cpu() is called at various locations. This _PSD fix doesn't apply at
other callers.
>
> Also the parens around it are not necessary here and is there any
I will remove it in the next rev.
> chance for having a proper symbol instead of the raw 0x19 in that
> check?
Unfortunately I didn't find a replacement. Only x86_vendor has an acronym. The rest
(fam/model/stepping) use numerical values, including in arch/x86 boot code.
>
> > + !acpi_pstate_strict) {
> > cpumask_clear(policy->cpus);
> > cpumask_set_cpu(cpu, policy->cpus);
> > cpumask_copy(data->freqdomain_cpus,
> > --
> > 2.26.2
> >