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 73FEBC531DC for ; Tue, 20 Aug 2024 14:06:48 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 267AC10E092; Tue, 20 Aug 2024 14:06:48 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="YJAbToZe"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.20]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6E30A10E092; Tue, 20 Aug 2024 14:06:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1724162808; x=1755698808; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=MrJaVukCblbAF5beCEIvjekC35gWWd06PuqyDAECCUg=; b=YJAbToZeQOxGr5AWIF5Ht+I8HyBM/z4/JMlE6gzof7R+LrLJcDiAlmB/ GJRLirOa3awiUS5PKusrUmVT9j+32sC0b7g0sUpZ4PM7FpYuznoO2E1WQ hWdd6UuD9hzDqxPjit6Wlek3M7B4WBQZICfYNKD0e0QaTd2shhCgCOUog OzW22mCBfBrp+F+Eyd/Y3SqHspWM6k4l5KSWZDa751GJTzXAaJh5o/h2v qRp+iT5LfwdVPY2FLyj3IZQlK0lq7O1aSTXGZVSxlhScvNn00r8mMq+Wc Voug3zgTCrzoPZDQxoHzEwja4tKfG07WvpAAZfSWhoPRQ76+aW53xrBfF A==; X-CSE-ConnectionGUID: T7TOmIzER+CWOPhXJhOiIw== X-CSE-MsgGUID: s+YCOvn0TtadbaMDtbVD9g== X-IronPort-AV: E=McAfee;i="6700,10204,11170"; a="22271127" X-IronPort-AV: E=Sophos;i="6.10,162,1719903600"; d="scan'208";a="22271127" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by orvoesa112.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Aug 2024 07:06:48 -0700 X-CSE-ConnectionGUID: J7DTI9/XSIq/QAtQsPVswQ== X-CSE-MsgGUID: 0ny/ekFmTUmrK9wF7VudZA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.10,162,1719903600"; d="scan'208";a="65610152" Received: from smile.fi.intel.com ([10.237.72.54]) by orviesa005.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Aug 2024 07:06:43 -0700 Received: from andy by smile.fi.intel.com with local (Exim 4.98) (envelope-from ) id 1sgPVQ-0000000HKD3-0nFm; Tue, 20 Aug 2024 17:06:40 +0300 Date: Tue, 20 Aug 2024 17:06:39 +0300 From: Andy Shevchenko To: Raag Jadav 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 v6] drm/i915/hwmon: expose fan speed Message-ID: References: <20240820062010.2000873-1-raag.jadav@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo 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 Tue, Aug 20, 2024 at 04:12:46PM +0300, Raag Jadav wrote: > On Tue, Aug 20, 2024 at 01:23:35PM +0300, Andy Shevchenko wrote: > > On Tue, Aug 20, 2024 at 11:50:10AM +0530, Raag Jadav wrote: ... > > > v6: Drop overflow logic (Andy) > > > Aesthetic adjustments (Badal) > > > > But it still has an issue with 64-bit division on 32-bit platforms, right? ... > > > + /* > > > + * Calculate fan speed in RPM by time averaging two subsequent > > > + * readings in minutes. > > > + * RPM = number of rotations * msecs per minute / time in msecs > > > + */ > > > + *val = DIV_ROUND_UP(rotations * (MSEC_PER_SEC * 60), time); > > > > ...somewhere here? > > Use div64_u64() instead? Or is there a better alternative? I don't know the code well to offer anything better. Probably for a starter you can switch to use DIV_ROUND_UP_ULL(). -- With Best Regards, Andy Shevchenko