From patchwork Mon Feb 17 20:39:43 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ahmad Fatoum X-Patchwork-Id: 13978642 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (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 1D394239594 for ; Mon, 17 Feb 2025 20:40:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739824858; cv=none; b=rdtrfFQuV+0L0ZmvvfeeCY1//XxkkPFAV2es/elhYY6VNiXhe38ZKDd4lkNZAefI9jVvPA6KCWdyFsYAIzIhnf3K+BHY9T5D40rEVrJj8EMgCi70qJHdlt6h1KFehhFZVl824kvE+pRoezav+v7ZGMxKH0utzmsEso0liZk5rMc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739824858; c=relaxed/simple; bh=+O2FsB2biFPebdsD/mYQegd/ubEfl2Q7jmEet+oj0VI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=RktVA8Z2vv9DlS+JNIwtHP53VQxyL3o2udZz4990yVNesvZqIIj1OmtprekZjxh9zzcWCA7O6xF/3urkC+ntgUZ969g2+kvOgPIaWEdlx5l2FEaynT3Lt+CW6029zyk5nQCzzzDfoJUDdi4zpD60uubbi8y6NWKylpUtWcoQaVY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1tk7uZ-0007oF-CW; Mon, 17 Feb 2025 21:40:15 +0100 Received: from dude05.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::54]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1tk7uX-001TFw-2v; Mon, 17 Feb 2025 21:40:13 +0100 Received: from localhost ([::1] helo=dude05.red.stw.pengutronix.de) by dude05.red.stw.pengutronix.de with esmtp (Exim 4.96) (envelope-from ) id 1tk7uX-000W9t-2Q; Mon, 17 Feb 2025 21:40:13 +0100 From: Ahmad Fatoum Date: Mon, 17 Feb 2025 21:39:43 +0100 Subject: [PATCH v3 03/12] docs: thermal: sync hardware protection doc with code Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250217-hw_protection-reboot-v3-3-e1c09b090c0c@pengutronix.de> References: <20250217-hw_protection-reboot-v3-0-e1c09b090c0c@pengutronix.de> In-Reply-To: <20250217-hw_protection-reboot-v3-0-e1c09b090c0c@pengutronix.de> To: Andrew Morton , Daniel Lezcano , Fabio Estevam , "Rafael J. Wysocki" , Zhang Rui , Lukasz Luba , Jonathan Corbet , Serge Hallyn , Liam Girdwood , Mark Brown , Matti Vaittinen , Benson Leung , Tzung-Bi Shih , Guenter Roeck , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-doc@vger.kernel.org, linux-security-module@vger.kernel.org, chrome-platform@lists.linux.dev, devicetree@vger.kernel.org, kernel@pengutronix.de, Ahmad Fatoum X-Mailer: b4 0.14.2 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: a.fatoum@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-security-module@vger.kernel.org Originally, the thermal framework's only hardware protection action was to trigger a shutdown. This has been changed a little over a year ago to also support rebooting as alternative hardware protection action. Update the documentation to reflect this. Fixes: 62e79e38b257 ("thermal/thermal_of: Allow rebooting after critical temp") Reviewed-by: Tzung-Bi Shih Reviewed-by: Matti Vaittinen Signed-off-by: Ahmad Fatoum --- Documentation/driver-api/thermal/sysfs-api.rst | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) diff --git a/Documentation/driver-api/thermal/sysfs-api.rst b/Documentation/driver-api/thermal/sysfs-api.rst index c803b89b7248f9f26ac24608b0144db5e9c2ddb4..f73de211bdced452b578fb77fb8707b8e59c9180 100644 --- a/Documentation/driver-api/thermal/sysfs-api.rst +++ b/Documentation/driver-api/thermal/sysfs-api.rst @@ -413,18 +413,21 @@ This function serves as an arbitrator to set the state of a cooling device. It sets the cooling device to the deepest cooling state if possible. -5. thermal_emergency_poweroff -============================= +5. Critical Events +================== -On an event of critical trip temperature crossing the thermal framework -shuts down the system by calling hw_protection_shutdown(). The -hw_protection_shutdown() first attempts to perform an orderly shutdown -but accepts a delay after which it proceeds doing a forced power-off -or as last resort an emergency_restart. +On an event of critical trip temperature crossing, the thermal framework +will trigger a hardware protection power-off (shutdown) or reboot, +depending on configuration. + +At first, the kernel will attempt an orderly power-off or reboot, but +accepts a delay after which it proceeds to do a forced power-off or +reboot, respectively. If this fails, ``emergency_restart()`` is invoked +as last resort. The delay should be carefully profiled so as to give adequate time for -orderly poweroff. +orderly power-off or reboot. -If the delay is set to 0 emergency poweroff will not be supported. So a -carefully profiled non-zero positive value is a must for emergency -poweroff to be triggered. +If the delay is set to 0, the emergency action will not be supported. So a +carefully profiled non-zero positive value is a must for the emergency +action to be triggered.