From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 61225C52D7B for ; Tue, 13 Aug 2024 05:45:29 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E9D8789D7C; Tue, 13 Aug 2024 05:45:28 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="IBBBzPNm"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.17]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8839010E294; Tue, 13 Aug 2024 05:45:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1723527928; x=1755063928; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=YwpuBVSFNyDvfJmlX29Z5q0LHVN5p+qw1by/SJOWLDk=; b=IBBBzPNmfKJfeSmquIWfuEhWAp9gNHVBpGccp2ZbodAyR05Z7wSXgLt+ 9j8QwioHk6/TDOPIy6+k8SgO8nnXtHk1rP1AkHM3wG8gLK+gQWXW2iwwN sBsXCIyLpSukoHI5u6Qjb46xiA1QYfk4h22XGRj5fx2K6jmBdmXO1fGv0 pAdNjrXmYbf9zysnDG9juPUFTOl3VYCWsGxkhRJmDUaxGblwR+bmpxYdX fa+kd9OG64w/PBdkAWUx6ZIGjUrHPQYPJ7+Vk54VAgNZfyZq2UHQrA8fh Gw5WuglU9zgrtmAiXqf66dTM3LIDizS5eLXC3sP9bJ/DalKqK54ocwDVI Q==; X-CSE-ConnectionGUID: tZsEBqaETGey7Ho7PODEcA== X-CSE-MsgGUID: oWSZpQQpTQWj/RUgQvIqSw== X-IronPort-AV: E=McAfee;i="6700,10204,11162"; a="21538927" X-IronPort-AV: E=Sophos;i="6.09,285,1716274800"; d="scan'208";a="21538927" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by fmvoesa111.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Aug 2024 22:45:27 -0700 X-CSE-ConnectionGUID: c9dFyZmbSLqazA9E/vH8Og== X-CSE-MsgGUID: oXlUV/1dR6SazqjesTO58g== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.09,285,1716274800"; d="scan'208";a="81776598" Received: from black.fi.intel.com ([10.237.72.28]) by fmviesa002.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Aug 2024 22:45:22 -0700 Date: Tue, 13 Aug 2024 08:45:19 +0300 From: Raag Jadav To: Andy Shevchenko Cc: jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com, rodrigo.vivi@intel.com, tursulin@ursulin.net, airlied@gmail.com, daniel@ffwll.ch, linux@roeck-us.net, andi.shyti@linux.intel.com, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org, anshuman.gupta@intel.com, badal.nilawar@intel.com, riana.tauro@intel.com, ashutosh.dixit@intel.com, karthik.poosa@intel.com Subject: Re: [PATCH v5] drm/i915/hwmon: expose fan speed Message-ID: References: <20240812081538.1457396-1-raag.jadav@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Mon, Aug 12, 2024 at 04:15:14PM +0300, Andy Shevchenko wrote: > On Mon, Aug 12, 2024 at 01:45:38PM +0530, Raag Jadav wrote: > > Add hwmon support for fan1_input attribute, which will expose fan speed > > in RPM. With this in place we can monitor fan speed using lm-sensors tool. > > > > $ sensors > > i915-pci-0300 > > Adapter: PCI adapter > > in0: 653.00 mV > > fan1: 3833 RPM > > power1: N/A (max = 43.00 W) > > energy1: 32.02 kJ > > ... > > > +static int > > +hwm_fan_read(struct hwm_drvdata *ddat, u32 attr, long *val) > > +{ > > + struct i915_hwmon *hwmon = ddat->hwmon; > > + struct hwm_fan_info *fi = &ddat->fi; > > + u64 rotations, time_now, time; > > + intel_wakeref_t wakeref; > > + u32 reg_val, pulses; > > + int ret = 0; > > + > > + if (attr != hwmon_fan_input) > > + return -EOPNOTSUPP; > > + > > + wakeref = intel_runtime_pm_get(ddat->uncore->rpm); > > + mutex_lock(&hwmon->hwmon_lock); > > + > > + reg_val = intel_uncore_read(ddat->uncore, hwmon->rg.fan_speed); > > + time_now = get_jiffies_64(); > > > + /* Handle HW register overflow */ > > + if (reg_val >= fi->reg_val_prev) > > + pulses = reg_val - fi->reg_val_prev; > > + else > > + pulses = UINT_MAX - fi->reg_val_prev + reg_val; > > Isn't it the abs_diff() reimplementation? Not exactly. This is specific to 32 bit register overflow, so we count from max value. Raag