From nobody Fri Dec 19 15:52:28 2025 Received: from esa2.hc1455-7.c3s2.iphmx.com (esa2.hc1455-7.c3s2.iphmx.com [207.54.90.48]) (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 5FCC91DA5F; Mon, 19 May 2025 07:29:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=207.54.90.48 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747639763; cv=none; b=Lo6Ya17hv7KJITuQZQvs+Uia9fuEYnnQjSZackDH6Y1aCp47JtBwd8vEyK2DgtQPRgCZWTvKpwJrEgzTebxxxuTmLRdlYnHUSeRMQT9dhA70DFIo0vYlIgGW4uKXvOXCBvKDE07/167xcjxQaImr82/ffb3Vfut1/k7DEAmRYU4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747639763; c=relaxed/simple; bh=iH+nmmU4D2Q00jNKLdtiGfpOSOS2rVBXD5mlABm6pso=; h=From:To:Subject:Date:Message-ID:MIME-Version; b=jrJ0g0feV1gJaJqSyV4qgq74gti/i3ig3gI4i0jCYNOvUc83D/1bhXnnNbpEwMMXZcxXadd/lImQZX60kYcVWvI3SqCbyohfe2bY2oYrbEKt/Lvs/yFO5Lr6eY3YpmNvVMTjgfvOhCRbMei1VDqHcZ73lxBAh0uCn9/Z2vi0aTk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=fujitsu.com; spf=pass smtp.mailfrom=fujitsu.com; dkim=pass (2048-bit key) header.d=fujitsu.com header.i=@fujitsu.com header.b=aBNBTtc+; arc=none smtp.client-ip=207.54.90.48 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=fujitsu.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=fujitsu.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=fujitsu.com header.i=@fujitsu.com header.b="aBNBTtc+" DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=fujitsu.com; i=@fujitsu.com; q=dns/txt; s=fj2; t=1747639762; x=1779175762; h=from:to:subject:date:message-id:mime-version: content-transfer-encoding; bh=iH+nmmU4D2Q00jNKLdtiGfpOSOS2rVBXD5mlABm6pso=; b=aBNBTtc+MHiSTumhPcxLUiVBgU+E5KxLI09oXOiPdRilF8t2aAairZK7 4ndZsiXUY96NCHTirQkmnL7B7eWscuB3dT3q+XR/SnB1at3BRx1JLpcMz +MbCS6FKXr4d6sbwk9QyKNIJDrsFMuHRn9OpgH8hp1cO/rtHGnbbBJsD1 Ca+ZqtYt0yMHJdif0ch1hLaPsnEZXf7Q1KMS1Jiz1TIm7zJsSf+YGzfLK MJ9zzRH+y0VadaRAUsMkUYZWywmsbCHGC3f+avMtOXRWt0ndGI4BAUYay wwoHkfcLP0Hk16fDIcCQnbcucT1fD/z0Qq0A2qoJsWltrACmDI4iIts+Y w==; X-CSE-ConnectionGUID: cGY1z9TzRq+UqnqKSUyfEA== X-CSE-MsgGUID: 5wJRuWrdT7acLME9mSHw6g== X-IronPort-AV: E=McAfee;i="6700,10204,11437"; a="199874952" X-IronPort-AV: E=Sophos;i="6.15,300,1739804400"; d="scan'208";a="199874952" Received: from unknown (HELO oym-r3.gw.nic.fujitsu.com) ([210.162.30.91]) by esa2.hc1455-7.c3s2.iphmx.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 May 2025 16:28:11 +0900 Received: from oym-m1.gw.nic.fujitsu.com (oym-nat-oym-m1.gw.nic.fujitsu.com [192.168.87.58]) by oym-r3.gw.nic.fujitsu.com (Postfix) with ESMTP id 3AC98C2260; Mon, 19 May 2025 16:28:08 +0900 (JST) Received: from oym-om4.fujitsu.com (oym-om4.o.css.fujitsu.com [10.85.58.164]) by oym-m1.gw.nic.fujitsu.com (Postfix) with ESMTP id 0C513D88D0; Mon, 19 May 2025 16:28:08 +0900 (JST) Received: from sm-arm-grace07.ssoft.mng.com (sm-x86-stp01.soft.fujitsu.com [10.124.178.20]) by oym-om4.fujitsu.com (Postfix) with ESMTP id B038A4005AE54; Mon, 19 May 2025 16:28:07 +0900 (JST) From: Shinji Nomoto To: Jean Delvare , Guenter Roeck , Jonathan Corbet , linux-hwmon@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Shinji Nomoto Subject: [PATCH] doc: hwmon: acpi_power_meter: Add information about enabling the power capping feature. Date: Mon, 19 May 2025 16:27:44 +0900 Message-ID: <20250519072756.1512244-1-fj5851bi@fujitsu.com> X-Mailer: git-send-email 2.43.0 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" To enable the power capping feature of the acpi_power_meter driver on systems other than IBM products, you must explicitly specify the force_cap_on module parameter. Add information to the documentation about enabling the power capping feature with this driver, including the above, to improve user convenience. Signed-off-by: Shinji Nomoto --- Documentation/hwmon/acpi_power_meter.rst | 25 +++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) diff --git a/Documentation/hwmon/acpi_power_meter.rst b/Documentation/hwmon= /acpi_power_meter.rst index 8628c1161015..334054afc498 100644 --- a/Documentation/hwmon/acpi_power_meter.rst +++ b/Documentation/hwmon/acpi_power_meter.rst @@ -37,9 +37,16 @@ arbitrary strings that ACPI provides with the meter. Th= e measures/ directory contains symlinks to the devices that this meter measures. =20 Some computers have the ability to enforce a power cap in hardware. If th= is is -the case, the `power[1-*]_cap` and related sysfs files will appear. When = the -average power consumption exceeds the cap, an ACPI event will be broadcast= on -the netlink event socket and a poll notification will be sent to the +the case, the `power[1-*]_cap` and related sysfs files will appear. +For information on enabling the power cap feature, refer to the description +of the "force_on_cap" option in the "Module Parameters" chapter. +To use the power cap feature properly, you need to set appropriate value +(in microWatts) to the `power[1-*]_cap` sysfs files. +The value must be within the range between the minimum value at `power[1-]= _cap_min` +and the maximum value at `power[1-]_cap_max (both in microWatts)`. + +When the average power consumption exceeds the cap, an ACPI event will be +broadcast on the netlink event socket and a poll notification will be sent= to the appropriate `power[1-*]_alarm` file to indicate that capping has begun, an= d the hardware has taken action to reduce power consumption. Most likely this w= ill result in reduced performance. @@ -52,3 +59,15 @@ follows: `power[1-*]_cap` will be notified if the firmware changes the power cap. `power[1-*]_interval` will be notified if the firmware changes the averagi= ng interval. + +Module Parameters +----------------- + +* force_cap_on: bool + Forcefully enable the power capping feature to spe= cify + the upper limit of the system's power consumption. + + By default, the driver's power capping feature is = only + enabled on IBM products. + Therefore, on other systems that support power cap= ping, + you will need to use the option to enable it. --=20 2.43.0