Re: [PATCH v6 0/3] cpufreq/amd-pstate: Fix EPP and auto_sel initialization

[Mario Limonciello]

On 6/9/26 02:29, Marco Scardovi wrote:
> Hi Mario, Prateek,
>
> no big deal making a v6 with your suggestions. I'm glad this series come to an end
> and everything works as expected.
>
> Here is v6 of the series addressing the feedback on EPP and auto_sel initialization.
> This version updates the metadata with Reviewed-by and Tested-by tags and applies
> a small commit message cleanup.
>
> Changes in v6:
> - Add K Prateek Nayak's Reviewed-by and Tested-by tags to all patches.
> - Drop the redundant paragraph from the commit message of Patch 3.
>
> Changes in v5:
> - Split the single unified patch into a 3-patch series:
>    - Patch 1: Change EPP helper return types to signed int and add error handling
>      in amd_pstate_epp_cpu_init().
>    - Patch 2: Remove the active-mode early return check in shmem_init_perf() to
>      ensure auto_sel is properly toggled on shared memory systems.
>    - Patch 3: Cache the initial firmware programmed EPP value in cppc_req_cached.
>
> Changes in v4:
> - Refactor EPP getter helper functions (msr_get_epp, shmem_get_epp, and
>    amd_pstate_get_epp) to return int, conforming to standard kernel practice
>    for value-or-negative-errno helpers.
> - Clean up commit message description to link error propagation directly to
>    EPP caching.
> - Execute the remaining shared-memory initialization path even when booting
>    in active mode, rather than bypassing it through an early return.
>
> Changes in v3:
> - Patch 1: Cache the firmware-programmed default EPP value at CPU EPP
>    initialization (resolving the boot-time false cache hit) and explicitly
>    toggle the AUTO_SEL_ENABLE register to 1 on shared memory systems,
>    rather than utilizing a state-tracking flag as proposed in v2.
> - Patch 2: Dropped as CPPC systems universally support EPP.
>
> Changes in v2:
> - Patch 1: Rename `epp_initialized` to `epp_hw_programmed` and add a comment
>    documenting the EPP cache guard optimization behavior.
> - Patch 2: Add comments explaining the uniform CPU capability check on x86,
>    handle EPP capability check errors robustly (only treat -EOPNOTSUPP as
>    unsupported, warn and assume supported for other errors to avoid false
>    negatives), and reject runtime active mode transitions at sysfs store time
>    (preventing the driver from being left in an unregistered state).
>
> Changes in v1:
> - Fix the boot-time CPPC EPP/auto_sel initialization regression in
>    shmem_set_epp() using a state tracking flag while preserving runtime
>    cache optimization.
> - Add an EPP capability check helper during initialization.
> - Fall back to passive mode at boot if EPP is not supported, and reject
>    transitions to active mode at runtime if EPP is not supported.
>
> Marco Scardovi (3):
>    cpufreq/amd-pstate: Fix EPP return type and handle errors during
>      initialization
>    cpufreq/amd-pstate: Toggle auto_sel in active mode on shared memory
>      systems
>    cpufreq/amd-pstate: Cache the firmware programmed EPP value
>
>   drivers/cpufreq/amd-pstate.c | 20 +++++++++++++-------
>   1 file changed, 13 insertions(+), 7 deletions(-)

Thanks, this all looks good now.  Appreciate the patience, and thanks 
for taking all the feedback into account.

I will add it to my tree and it will go for next cycle (7.3).