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 92B50C531DF for ; Thu, 22 Aug 2024 07:28:51 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 8502610E7CB; Thu, 22 Aug 2024 07:28:48 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="O8dEVsvb"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.9]) by gabe.freedesktop.org (Postfix) with ESMTPS id 06B4010E7C5; Thu, 22 Aug 2024 07:28:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1724311727; x=1755847727; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=JOmB3H1enfZrkteU613aUSjuKOs8i3PjWruFo3Cqz08=; b=O8dEVsvbmbzFX8HsYfA+1ksejZsh2ul6ubInl7fzX5z89KaWO97yFbVz QT2JhNW7OX7a6pgM+HVNweqkYMzzyz8nZQauyVIdWAdbm4FHxj5XFkS+y 5DFZniDp58YETA6QMgXKaGkVi/F10RSWHQtIfZF0AWYt5uacGAuD/uE+s yczaklqwCh+eQi3I8QsgT9a02WxgxvU+/peUHmgd5xcagbZ0G6Siql00K xgVRZlJjfGDRwiWtuUWhsIMp57Sqo0ndQMfMd7EHn34VzQKDKEH1dJpa2 Y9huaKt4pmKEYVWmbTFR+A/rR6cG53dIrV/V9hHCxfB346RNncRrgo9dQ w==; X-CSE-ConnectionGUID: AnazrIcTQfiqN+ENUXlLxg== X-CSE-MsgGUID: veFryIVzSVmQ87TtEEU/Rw== X-IronPort-AV: E=McAfee;i="6700,10204,11171"; a="33371615" X-IronPort-AV: E=Sophos;i="6.10,166,1719903600"; d="scan'208";a="33371615" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by fmvoesa103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Aug 2024 00:28:46 -0700 X-CSE-ConnectionGUID: JW9dLWMFT2CEn/TH1fuMtw== X-CSE-MsgGUID: BbNyJbfDQvmkLO66SzP5Lg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.10,166,1719903600"; d="scan'208";a="65698857" Received: from black.fi.intel.com ([10.237.72.28]) by fmviesa005.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Aug 2024 00:28:41 -0700 Date: Thu, 22 Aug 2024 10:28:38 +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 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: 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 05:06:39PM +0300, Andy Shevchenko wrote: > 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: > > > > > > 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(). This one seems to work. Does it warrant an explanation here? Raag