From nobody Sat Feb 7 14:34:24 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D45FA2F6931; Tue, 6 Jan 2026 05:15:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767676513; cv=none; b=eAzql24wqhaqXW0ACYwCmxfxXd7PkjZcKE6wCMa2ZzUCO7OFtmSHRhHCKKbAPIrPeXPgM5xasx38onrRDTIkEJhrozYB6We/8oIhNtp1FLq4oJTh5Yyqz6QcnSrJ+E2mHHJWp86V+4SW/Q3AqcSPEeDGMjtl4f/hk3MvJoicQkU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767676513; c=relaxed/simple; bh=Y/AjsLq+32sMPVqzYF2M2p7J3XWlM6ewKZ1fE+wvH+c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AAWmN5A/6ig9Gm4VAjzM1eDpk+e4/P14Q+g23gEZlEBjWTXI6MtjF8tONEruD2HUb0tZHKx0CyCcQoh5f/VQlOE1Moux55o2jeR37ym9J8mL8WZ3v/jvFlasJJPXnWiVxxFzytcVTTafoBJb+gohpUO5GOREAmSTWPXYCy0Kv5A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pJZYzgFU; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="pJZYzgFU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 182C9C19421; Tue, 6 Jan 2026 05:15:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1767676513; bh=Y/AjsLq+32sMPVqzYF2M2p7J3XWlM6ewKZ1fE+wvH+c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pJZYzgFUiuPvcqZMuNcZ+A3g1lrahCaBKRupvomINRifLNUjDCKvD/PlTfz/Y3y3w TriTGybexEhBXm+vaA32x7fRxoBqpDAaFpXefwgFpr/ZS2CymLgcspqT2iElH88hnP s34RAHO6F8cL8kmlJcJ+CntwrsAkxgNDjdzY2BSFoShRMd+WpY5iJLrelDb5GaWoiK 02vS+3AFIq5F8ujrie9aHsGLL6ZdWmsxo7i7eezqMcJRqKC9NH+n2CM17IyU3ICdOy Vt8HIdgCW+M7X+nBLiqS2pp0hNN8NWa0BRfqxA2mFAtk3cAkF6bMy0QMT27isg6KX6 7MyuRumN/jh0Q== From: "Mario Limonciello (AMD)" To: "Gautham R . Shenoy" Cc: Perry Yuan , linux-kernel@vger.kernel.org (open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)), linux-pm@vger.kernel.org (open list:CPU FREQUENCY SCALING FRAMEWORK), Mario Limonciello Subject: [PATCH v5 2/5] cpufreq/amd-pstate: add kernel command line to override dynamic epp Date: Mon, 5 Jan 2026 23:14:38 -0600 Message-ID: <20260106051441.60093-3-superm1@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260106051441.60093-1-superm1@kernel.org> References: <20260106051441.60093-1-superm1@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Mario Limonciello Add `amd_dynamic_epp=3Denable` and `amd_dynamic_epp=3Ddisable` to override the kernel configuration option `CONFIG_X86_AMD_PSTATE_DYNAMIC_EPP` locally. Signed-off-by: Mario Limonciello --- Documentation/admin-guide/kernel-parameters.txt | 7 +++++++ Documentation/admin-guide/pm/amd-pstate.rst | 7 +++++++ drivers/cpufreq/amd-pstate.c | 11 +++++++++++ 3 files changed, 25 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentatio= n/admin-guide/kernel-parameters.txt index a8d0afde7f85a..d7d547bbda430 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -490,6 +490,13 @@ Kernel parameters disable Disable amd-pstate preferred core. =20 + amd_dynamic_epp=3D + [X86] + disable + Disable amd-pstate dynamic EPP. + enable + Enable amd-pstate dynamic EPP. + amijoy.map=3D [HW,JOY] Amiga joystick support Map of devices attached to JOY0DAT and JOY1DAT Format: , diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/ad= min-guide/pm/amd-pstate.rst index 5aa9fb77a078c..df4607b6a5f62 100644 --- a/Documentation/admin-guide/pm/amd-pstate.rst +++ b/Documentation/admin-guide/pm/amd-pstate.rst @@ -438,6 +438,13 @@ For systems that support ``amd-pstate`` preferred core= , the core rankings will always be advertised by the platform. But OS can choose to ignore that via= the kernel parameter ``amd_prefcore=3Ddisable``. =20 +``amd_dynamic_epp`` + +When AMD pstate is in auto mode, dynamic EPP will control whether the kern= el +autonomously changes the EPP mode. The default is configured by +``CONFIG_X86_AMD_PSTATE_DYNAMIC_EPP`` but can be explicitly enabled with +``amd_pstate_epp=3Denable`` or disabled with ``amd_pstate_epp=3Ddisable``. + User Space Interface in ``sysfs`` - General =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =20 diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index 26a8552581c57..7dd50b5825d78 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -1992,8 +1992,19 @@ static int __init amd_prefcore_param(char *str) return 0; } =20 +static int __init amd_dynamic_epp_param(char *str) +{ + if (!strcmp(str, "disable")) + dynamic_epp =3D false; + if (!strcmp(str, "enable")) + dynamic_epp =3D true; + + return 0; +} + early_param("amd_pstate", amd_pstate_param); early_param("amd_prefcore", amd_prefcore_param); +early_param("amd_dynamic_epp", amd_dynamic_epp_param); =20 MODULE_AUTHOR("Huang Rui "); MODULE_DESCRIPTION("AMD Processor P-state Frequency Driver"); --=20 2.43.0