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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 1692CF3380C for ; Tue, 17 Mar 2026 07:34:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ovos5ZgwjwedhdOR93lPLFH4Q9AxTbpu756HtPKvsUo=; b=aUOWhMPHKrpxJWVj2wD2rwVo2j facO2DYbHcmLNv1bRhtgc/U42mP54+QnP0a0w3SHuaXFqLQKNvsKLfO/0lqbwmXNJuE+WrmlolCCh AVkolXtDhiaUG63N1qIcKx+olT933s7o1iFkHkCqUoeTbUJZKsht9tGfp1PlSPVZ3N90ZdotEVjUw Q//bP00iqKrGirC3bPp50UsMoXPlvn22KWfc+uhOF3VChfqFAYSyqKmma58UIzgCYDNtBwaL9uLWq NcVTrg2A0ftZ67O/yaXHbPbnbG6vPyT4HyiYIcYUlFNwDa95/xEdTLN6qgE9cxwjL76SjS2/TpRFw k4NMk6MA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w2Owj-00000005a8F-1yZQ; Tue, 17 Mar 2026 07:34:33 +0000 Received: from mgamail.intel.com ([192.198.163.14]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1w2Owg-00000005a7R-2sbF for linux-arm-kernel@lists.infradead.org; Tue, 17 Mar 2026 07:34:31 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1773732869; x=1805268869; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=1OJtUNEamh5vO3iFIrEXYFak4q7SIt7T2aherzADZ/g=; b=Nkdm9SyOViFWsr8bc/7hJpvoF7SB48Z2qkSaYCaeJ1Elc8yfWVlQMxhF NsNf9W7ooGCJbeCFjrqJAkgVHFKDEW1J2sf0mnGThIWR5kuM791lL7f9y 8xroVo2+5QlsgGnahCbhydi7pvH/HZfO3ywfXMToL68NPo4cwUcFB5Vdx dY9qDFg6lc+xPITVhn0hbrANOtQQt+R4rrQJfyn9bxgSfR1gaJ55d+mEd W3dnjljelu6sVSNF0fYVyKnXlky/WJSPAzdXYG57SfSq06PxsQKChHKjt WlhXa7XT788roGX84Ra+sTJ18SI/nijW443Ayvc/AjYUcaNu64p6jx8WS w==; X-CSE-ConnectionGUID: bGlpCNEZSxGCHDHoDJEESA== X-CSE-MsgGUID: P5hKE3FGS1WeXqUWu3xH9A== X-IronPort-AV: E=McAfee;i="6800,10657,11731"; a="74835522" X-IronPort-AV: E=Sophos;i="6.23,124,1770624000"; d="scan'208";a="74835522" Received: from orviesa003.jf.intel.com ([10.64.159.143]) by fmvoesa108.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Mar 2026 00:34:27 -0700 X-CSE-ConnectionGUID: l6i/QyKCQ2+Qh0zbsAMaDQ== X-CSE-MsgGUID: E2hgBnOgTvOTItdc81+GLQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,124,1770624000"; d="scan'208";a="226306582" Received: from abityuts-desk.ger.corp.intel.com (HELO localhost) ([10.245.245.97]) by ORVIESA003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Mar 2026 00:34:20 -0700 Date: Tue, 17 Mar 2026 09:34:17 +0200 From: Andy Shevchenko To: Wolfram Sang Cc: Douglas Anderson , Greg Kroah-Hartman , "Rafael J . Wysocki" , Danilo Krummrich , stable@vger.kernel.org, Andrew Lunn , Daniel Scally , "David S. Miller" , Eric Dumazet , Fabio Estevam , Frank Li , Heikki Krogerus , Heiner Kallweit , Jakub Kicinski , Len Brown , Mark Brown , Paolo Abeni , Pengutronix Kernel Team , Rob Herring , Russell King , Sakari Ailus , Saravana Kannan , Sascha Hauer , devicetree@vger.kernel.org, driver-core@lists.linux.dev, imx@lists.linux.dev, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH] device property: Make modifications of fwnode "flags" thread safe Message-ID: References: <20260316154159.1.I0a4d03104ecd5103df3d76f66c8d21b1d15a2e38@changeid> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260317_003430_742097_5A567E0A X-CRM114-Status: GOOD ( 16.55 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Mar 17, 2026 at 08:26:53AM +0100, Wolfram Sang wrote: ... > Thanks for tackling this issue! I agree it should be fixed, just > wondered about one thing: > > > While flags are often modified while under the "fwnode_link_lock", > > this is not universally true. > > Is it a possibility to use the lock in all code paths instead? > Because... > > > struct list_head consumers; > > - u8 flags; > > + unsigned long flags; > > ... this change costs some memory on every system. Maybe it can be > avoided? How much memory does it cost? On most 64-bit architectures is +4 bytes, rarely +0 bytes, on m68k it might be +2bytes. On 32-bit it most likely +0 bytes. I expect that 64-bit machines will cope with this bump. -- With Best Regards, Andy Shevchenko