cpufreq: Set policy->min and max as real QoS constraints [LWN.net]

From:		Pierre Gondois <pierre.gondois-AT-arm.com>
To:		linux-kernel-AT-vger.kernel.org
Subject:		[PATCH v3 0/4] cpufreq: Set policy->min and max as real QoS constraints
Date:		Thu, 28 May 2026 11:09:02 +0200
Message-ID:		<20260528090913.2759118-1-pierre.gondois@arm.com>
Cc:		Jie Zhan <zhanjie9-AT-hisilicon.com>, Lifeng Zheng <zhenglifeng1-AT-huawei.com>, Ionela Voinescu <ionela.voinescu-AT-arm.com>, Sumit Gupta <sumitg-AT-nvidia.com>, Zhongqiu Han <zhongqiu.han-AT-oss.qualcomm.com>, Pierre Gondois <pierre.gondois-AT-arm.com>, "Rafael J. Wysocki" <rafael-AT-kernel.org>, Viresh Kumar <viresh.kumar-AT-linaro.org>, Jonathan Corbet <corbet-AT-lwn.net>, Shuah Khan <skhan-AT-linuxfoundation.org>, Huang Rui <ray.huang-AT-amd.com>, Mario Limonciello <mario.limonciello-AT-amd.com>, Perry Yuan <perry.yuan-AT-amd.com>, K Prateek Nayak <kprateek.nayak-AT-amd.com>, Srinivas Pandruvada <srinivas.pandruvada-AT-linux.intel.com>, Len Brown <lenb-AT-kernel.org>, Saravana Kannan <saravanak-AT-kernel.org>, linux-pm-AT-vger.kernel.org, linux-doc-AT-vger.kernel.org
Archive-link:		Article

This patch is a follow-up from the serie:
- [PATCH v6 0/4] cpufreq: Introduce boost frequency QoS
https://lore.kernel.org/lkml/20260317101753.2284763-1-pie...

v3:
- Added Reviewed-by tags
- Return 0 on cpufreq_policy_init_qos() success instead of
  a random positive value
- Moved policy->min/max assignment out of cpufreq_policy_init_qos()
- Updated documentation
v2:
- Split the patch in multiple steps
- Replace min/max -> min_freq/max_freq
- Add references to commit 521223d8b3ec ("cpufreq: Fix initialization
  of min and max frequency QoS requests") to explain the intent
  of the patch
- Update documentation (cpu-drivers.rst)
- Set default policy->min/max values before the call to
  blocking_notifier_call_chain()
- Create a new cpufreq_policy_init_qos() function to put all
  the QoS and policy->min/max logic inside.
- Didn't add Sumit's reviewed-by as the patches changed a bit.
v1:
https://lore.kernel.org/lkml/20260423084731.1090384-1-pie...

Pierre Gondois (4):
  cpufreq: Extract cpufreq_policy_init_qos() function
  cpufreq: Set default policy->min/max values for all drivers
  cpufreq: Remove driver default policy->min/max init
  cpufreq: Use policy->min/max init as QoS request

 Documentation/cpu-freq/cpu-drivers.rst |  9 +++-
 drivers/cpufreq/amd-pstate.c           | 14 +++---
 drivers/cpufreq/cppc_cpufreq.c         |  5 +-
 drivers/cpufreq/cpufreq-nforce2.c      |  4 +-
 drivers/cpufreq/cpufreq.c              | 68 ++++++++++++++++++--------
 drivers/cpufreq/freq_table.c           |  7 ++-
 drivers/cpufreq/gx-suspmod.c           |  2 +-
 drivers/cpufreq/intel_pstate.c         |  3 --
 drivers/cpufreq/pcc-cpufreq.c          | 10 ++--
 drivers/cpufreq/pxa3xx-cpufreq.c       |  5 +-
 drivers/cpufreq/sh-cpufreq.c           |  6 +--
 drivers/cpufreq/virtual-cpufreq.c      |  5 +-
 12 files changed, 77 insertions(+), 61 deletions(-)

--
2.43.0