Re: [PATCH v5 2/3] cpufreq/amd-pstate: Toggle auto_sel in active mode on shared memory systems
From: K Prateek Nayak
Date: Tue Jun 09 2026 - 00:53:08 EST
Hello Marco,
On 6/8/2026 1:01 PM, Marco Scardovi wrote:
> On shared memory systems, the EPP configuration path (handled via
> cppc_set_epp_perf()) is responsible for toggling on the CPPC autonomous
> selection register (auto_sel).
>
> Currently, shmem_init_perf() returns early without doing any of the auto_sel
> configuration steps if cppc_state is AMD_PSTATE_ACTIVE. This skips enabling
> auto_sel, leaving the CPU in non-autonomous mode.
>
> Remove the early return check in shmem_init_perf() when cppc_state is
> AMD_PSTATE_ACTIVE. Toggling auto_sel is necessary for the active mode on
> shared memory systems to function based on the ACPI spec for CPPC v2 and
> below.
>
> Fixes: 2dd6d0ebf740 ("cpufreq: amd-pstate: Add guided autonomous mode")
> Assisted-by: Antigravity:gemini-3.5-flash
> Signed-off-by: Marco Scardovi <scardracs@xxxxxxxxxxx>
Feel free to include:
Reviewed-by: K Prateek Nayak <kprateek.anayk@xxxxxxx>
--
Thanks and Regards,
Prateek