On Tue, Nov 5, 2024 at 9:17 PM Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote:
>
> On Mon, Nov 4, 2024 at 11:29 PM Mario Limonciello <superm1@xxxxxxxxxx> wrote:
> >
> > From: Mario Limonciello <mario.limonciello@xxxxxxx>
> >
> > arch_init_invariance_cppc() is called at the end of
> > acpi_cppc_processor_probe() in order to configure frequency invariance
> > based upon the values from _CPC.
> >
> > This however doesn't work on AMD CPPC shared memory designs that have
> > AMD preferred cores enabled because _CPC needs to be analyzed from all
> > cores to judge if preferred cores are enabled.
> >
> > This issue manifests to users as a warning since commit 21fb59ab4b97
> > ("ACPI: CPPC: Adjust debug messages in amd_set_max_freq_ratio() to warn"):
> > ```
> > Could not retrieve highest performance (-19)
> > ```
> >
> > However the warning isn't the cause of this, it was actually
> > commit 279f838a61f9 ("x86/amd: Detect preferred cores in
> > amd_get_boost_ratio_numerator()") which exposed the issue.
> >
> > To fix this problem, change arch_init_invariance_cppc() into a new weak
> > symbol that is called at the end of acpi_processor_driver_init().
> > Each architecture that supports it can declare the symbol to override
> > the weak one.
>
> "Define it for x86, in arch/x86/kernel/acpi/cppc.c, and for all of the
> architectures using the generic arch_topology.c code."
I've added this to the patch changelog and queued it up as a 6.12 fix.
Thanks!
