From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.10]) (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 1CDCA24397A; Sun, 28 Dec 2025 20:03:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766952206; cv=none; b=gnO7vXBL/Ni2Ht0cyO29E9yE50TBkfax3EZlNnYpJCch3JauGBdCePx/KbQ9JEUIRs1DGzau4qluw400Zkg2zQxr6dB3JeRlxtUk2Mnz9CO61NwxNxKYeTtvNQIyXnfgYgz3Pp6mraQxZVb0MQMu0l66OXAOhjkQc+gvbk7M/t4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766952206; c=relaxed/simple; bh=fv+ApKFw4PdI2rUGcp4PkvG+omFm7kWaVklPvZYXQPQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=K/hciR6qjwlifv49cug1aVbM1cyTQd6euuvcgffE2/j3dJtvS0mJ7tX4vxLg6RBj/34bmoA0pqEdqYGm8yTTWZTPzEfKV3CtF+xIrcJtGfDvLjr40CbAOEjJQNpHDafLU6xkG0ae4yz12g4hdMM4a8RLrfodgxfGpVWCse3wSnU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=WfD+zc0Z; arc=none smtp.client-ip=198.175.65.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="WfD+zc0Z" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1766952205; x=1798488205; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=fv+ApKFw4PdI2rUGcp4PkvG+omFm7kWaVklPvZYXQPQ=; b=WfD+zc0Zz95JAVA7oEiV5Dprvc+g0WiXzqMbsRC2mp/Fh8inV8hZxx7r zh4IvwbOT/+40C3sgN9DCmLZ1L+NCCWbaowkFiRm+3sCOFDL3hLkCoiIt YRZjRHepyDY3PRm96au4xHXZW5zPDfK+gYlYatAlQtiscTaoO/79evQFz hNjtzFjxf+UV7a595dlzahGk1DT24IcJmJRr5F6LePN+cS2jyfFsdrYzu 7UK2tISuOmJQrIkMYzSOKc4cDcdSyugTVuGacaNsIYw1kXNZZ52YuQ0vJ ZWkSYxSaDCEcTRv0TmPekpq+O3sMZcbJu+m6wYpVqsrXaptupuPUxejw7 g==; X-CSE-ConnectionGUID: Ps35crTfTb+fOeBrSDD4KA== X-CSE-MsgGUID: 8esl0MtsQWmp8RfSQBgJsw== X-IronPort-AV: E=McAfee;i="6800,10657,11655"; a="86004961" X-IronPort-AV: E=Sophos;i="6.21,184,1763452800"; d="scan'208";a="86004961" Received: from orviesa002.jf.intel.com ([10.64.159.142]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Dec 2025 12:03:24 -0800 X-CSE-ConnectionGUID: Ns2ygDZMTL+M73gbSS31gQ== X-CSE-MsgGUID: G0V5BFxBQ4m6AD/sLLU/Mw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,184,1763452800"; d="scan'208";a="231435972" Received: from abityuts-desk.ger.corp.intel.com (HELO localhost) ([10.245.244.236]) by orviesa002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Dec 2025 12:03:22 -0800 Date: Sun, 28 Dec 2025 22:03:19 +0200 From: Andriy Shevencho To: Jonathan Brophy Cc: Jonathan Brophy , lee Jones , Pavel Machek , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Radoslav Tsvetkov , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-leds@vger.kernel.org" Subject: Re: [RFC PATCH 0/2] leds: Add optional instance identifier for deterministic naming Message-ID: References: <20251228182252.1550173-1-professorjonny98@gmail.com> Precedence: bulk X-Mailing-List: linux-leds@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo On Sun, Dec 28, 2025 at 07:14:09PM +0000, Jonathan Brophy wrote: > >Hmm... I think the research missed the udev + sysfs approach as done for the > > >networking devices. Hence the question: do we have enough data in sysfs for > > >leds to understand their HW connections / semantics? ... > **What we'd need for udev to work:** > > We'd need to expose something like: > š /sys/class/leds/lan:green_23/dt_path -> /leds/led-port23 > š /sys/class/leds/lan:green_23/hardware_id > > But this has problems: > 1. Not all platforms use DT (ACPI systems) Ah, forgot to comment on this. ACPI incorporates the way of key=value properties in the similar way DT does. So it's not a good point. > 2. Adds complexity to LED core for every driver > 3. Requires userspace policy to parse and create symlinks This is what udev is for. > 4. Still depends on non-deterministic suffix Same as #3. So, this leaves us only #2. Which is a weak argument in my opinion. > The instance identifier solves this with much less effort. But as I already replied, your approach is also okay to me. -- With Best Regards, Andy Shevchenko