| From: |
| Sumit Gupta <sumitg-AT-nvidia.com> |
| To: |
| <rafael-AT-kernel.org>, <viresh.kumar-AT-linaro.org>, <pierre.gondois-AT-arm.com>, <zhenglifeng1-AT-huawei.com>, <ionela.voinescu-AT-arm.com>, <lenb-AT-kernel.org>, <robert.moore-AT-intel.com>, <corbet-AT-lwn.net>, <rdunlap-AT-infradead.org>, <ray.huang-AT-amd.com>, <gautham.shenoy-AT-amd.com>, <mario.limonciello-AT-amd.com>, <perry.yuan-AT-amd.com>, <zhanjie9-AT-hisilicon.com>, <linux-pm-AT-vger.kernel.org>, <linux-acpi-AT-vger.kernel.org>, <linux-doc-AT-vger.kernel.org>, <acpica-devel-AT-lists.linux.dev>, <linux-kernel-AT-vger.kernel.org> |
| Subject: |
| [PATCH v7 0/7] Enhanced autonomous selection and improvements |
| Date: |
| Thu, 29 Jan 2026 16:18:10 +0530 |
| Message-ID: |
| <20260129104817.3752340-1-sumitg@nvidia.com> |
| Cc: |
| <linux-tegra-AT-vger.kernel.org>, <treding-AT-nvidia.com>, <jonathanh-AT-nvidia.com>, <vsethi-AT-nvidia.com>, <ksitaraman-AT-nvidia.com>, <sanjayc-AT-nvidia.com>, <nhartman-AT-nvidia.com>, <bbasu-AT-nvidia.com>, <sumitg-AT-nvidia.com> |
| Archive-link: |
| Article |
As discussed in [7], v5 was split into two parts. This is part 1.
- Patch 1-3 from v6: Applied by Rafael for 6.20.
- Remaining patches: Included in this v7 with review comments addressed.
Part 2 (v5 patches 8-11) will follow separately.
This patch series adds sysfs interfaces for CPPC min_perf, max_perf,
and perf_limited registers, along with supporting ACPI APIs and
improvements for the cppc_cpufreq driver.
CPPC autonomous mode (auto_sel) enables hardware-driven CPU performance
scaling using Energy Performance Preference (EPP) hints. Currently,
there's limited runtime control and visibility into CPPC performance
registers.
This series addresses these gaps by:
1. Exposing min_perf/max_perf registers via sysfs (as frequency in kHz)
to allow fine-grained performance bounds control in autonomous mode.
2. Exposing perf_limited register to detect and clear throttling events.
It also includes code improvements: new APIs for reading performance
controls, a warning for missing mandatory DESIRED_PERF register, and
extended epp_perf support.
The patches are grouped as below:
- Patch 1: Add cppc_get_perf() API (independent).
- Patch 2: Warn on missing mandatory DESIRED_PERF (independent).
- Patch 3: Extend cppc_set_epp_perf for FFH/SystemMemory (independent)
- Patch 4-5: APIs, sysfs for min/max_perf, perf_limited (independent)
- Patch 6: Doc for min/max_perf and perf_limited (depends on 4-5)
- Patch 7: Update cached perf_ctrls on sysfs write (independent).
---
v6[7] -> v7:
- patch 1-3 (v6): Dropped as they were applied by Rafael for 6.20.
- patch 2 (v7): Added new patch to warn on missing DESIRED_PERF as
suggested by Pierre.
- patch 4, 7 (v7): Removed mutex from sysfs store functions as
policy->rwsem already provides synchronization.
- patch 4 (v7): Added validation checks in store_min/max_perf.
Sumit Gupta (7):
ACPI: CPPC: Add cppc_get_perf() API to read performance controls
ACPI: CPPC: Warn on missing mandatory DESIRED_PERF register
ACPI: CPPC: Extend cppc_set_epp_perf() for FFH/SystemMemory
ACPI: CPPC: add APIs and sysfs interface for min/max_perf
ACPI: CPPC: add APIs and sysfs interface for perf_limited
cpufreq: CPPC: Add sysfs for min/max_perf and perf_limited
cpufreq: CPPC: Update cached perf_ctrls on sysfs write
.../ABI/testing/sysfs-devices-system-cpu | 44 ++++
drivers/acpi/cppc_acpi.c | 214 +++++++++++++++++-
drivers/cpufreq/cppc_cpufreq.c | 207 ++++++++++++++++-
include/acpi/cppc_acpi.h | 40 ++++
4 files changed, 500 insertions(+), 5 deletions(-)
[1] https://lore.kernel.org/lkml/20250211103737.447704-1-sumi...
[2] https://lore.kernel.org/lkml/20250823200121.1320197-1-sum...
[3] https://lore.kernel.org/lkml/20251001150104.1275188-1-sum...
[4] https://lore.kernel.org/lkml/20251105113844.4086250-1-sum...
[5] https://lore.kernel.org/lkml/20251223121307.711773-1-sumi...
[6] https://lore.kernel.org/lkml/20260120145623.2959636-1-sum...
[7] https://lore.kernel.org/lkml/66f58f43-631b-40a0-8d42-4e90...
--
2.34.1
