[PATCH v3 0/5] AMD Pstate driver Urgent Change

From: Perry Yuan <Perry.Yuan@amd.com>
To: <rafael.j.wysocki@intel.com>, <ray.huang@amd.com>,
	<viresh.kumar@linaro.org>, <Mario.Limonciello@amd.com>
Cc: <Nathan.Fontenot@amd.com>, <Alexander.Deucher@amd.com>,
	<Deepak.Sharma@amd.com>, <Shimmer.Huang@amd.com>,
	<Li.Meng@amd.com>, <Xiaojian.Du@amd.com>, <wyes.karny@amd.com>,
	<gautham.shenoy@amd.com>, <ananth.narayan@amd.com>,
	<linux-pm@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	Perry Yuan <Perry.Yuan@amd.com>
Subject: [PATCH v3 0/5] AMD Pstate driver Urgent Change
Date: Thu, 17 Nov 2022 15:35:36 +0800	[thread overview]
Message-ID: <20221117073541.3350600-1-Perry.Yuan@amd.com> (raw)

The patchset changed amd-pstate driver as built-in type to resolve the
driver loading sequence problem, otherwise the acpi-cpufreq driver will
be loaded as the default cpufreq scaling driver instead of amd-pstate.

Some new kernel parameters are added to allow user to disable pstate driver
and load driver with passive mode which use governors to do the
frequency scaling control.

* `amd_pstate=disabled` or no parameters will not load pstate driver.
* `amd_pstate=passive` will load pstate driver with passive mode.

Set the `amd_pstate` driver disabled by default because of performance
degradation on a number of AMD ASICs in the passive mode driver,
especially the shared memory support processors.

EPP support for the amd_pstate driver is under review. With EPP support,
the said performance issue is resolved. Once that gets upstream,
the `active` mode amd_pstate_epp driver may be enabled by default.

Changes from v2:
 * pick up Acked-by flag of Huang Rui
 * fix typo in the cover letter

Changes from v1:
 * fix commit info in v1 patch PATCH 4/5
 * pick up Reviewed-by flag of Gautham R. Shenoy
 * pick up Tested-by flag of  Wyes Karny

v2: https://lore.kernel.org/lkml/20221117071910.3347052-1-Perry.Yuan@amd.com/
v1: https://lore.kernel.org/lkml/20221117024955.3319484-1-Perry.Yuan@amd.com/

Perry Yuan (4):
  cpufreq: amd-pstate: change amd-pstate driver to be built-in type
  cpufreq: amd-pstate: add amd-pstate driver parameter for mode
    selection
  Documentation: amd-pstate: add driver working mode introduction
  Documentation: add amd-pstate kernel command line options

Wyes Karny (1):
  cpufreq: amd-pstate: cpufreq: amd-pstate: reset MSR_AMD_PERF_CTL
    register at init

 .../admin-guide/kernel-parameters.txt         | 11 +++++
 Documentation/admin-guide/pm/amd-pstate.rst   | 30 +++++-------
 drivers/cpufreq/Kconfig.x86                   |  2 +-
 drivers/cpufreq/amd-pstate.c                  | 49 +++++++++++++------
 4 files changed, 59 insertions(+), 33 deletions(-)

-- 
2.25.1