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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C1BDC4741F for ; Sun, 27 Sep 2020 00:29:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F0E012371F for ; Sun, 27 Sep 2020 00:29:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727709AbgI0A3j (ORCPT ); Sat, 26 Sep 2020 20:29:39 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:57522 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726426AbgI0A3i (ORCPT ); Sat, 26 Sep 2020 20:29:38 -0400 Received: from andrew by vps0.lunn.ch with local (Exim 4.94) (envelope-from ) id 1kMKZL-00GKmw-0e; Sun, 27 Sep 2020 02:29:35 +0200 Date: Sun, 27 Sep 2020 02:29:35 +0200 From: Andrew Lunn To: Marek Behun Cc: netdev , linux-leds@vger.kernel.org, David Miller , Russell King Subject: Re: Request for Comment: LED device naming for netdev LEDs Message-ID: <20200927002935.GA3889809@lunn.ch> References: <20200927004025.33c6cfce@nic.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200927004025.33c6cfce@nic.cz> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sun, Sep 27, 2020 at 12:40:25AM +0200, Marek Behun wrote: > Hi, > > linux-leds is trying to create a consistent naming mechanism for LEDs > The schema is: > device:color:function > for example > system:green:power > keyboard0:green:capslock > > But we are not there yet. > > LEDs are often dedicated to specific function by manufacturers, for > example there can be an icon or a text next to the LED on the case of a > router, indicating that the LED should blink on activity on a specific > ethernet port. > > This can be specified in device tree via the trigger-sources property. > > We therefore want to select the device part of the LED name to > correspond to the device it should trigger to according to the > manufacturer. > > What I am wondering is how should we select a name for the device part > of the LED for network devices, when network namespaces are enabled. > > a) We could just use the interface name (eth0:yellow:activity). The > problem is what should happen when the interface is renamed, or > moved to another network namespace. > Pavel doesn't want to complicate the LED subsystem with LED device > renaming, nor, I think, with namespace mechanism. I, for my part, am > not opposed to LED renaming, but do not know what should happen when > the interface is moved to another namespace. > > b) We could use the device name, as in struct device *. But these names > are often too long and may contain characters that we do not want in > LED name (':', or '/', for example). > > c) We could create a new naming mechanism, something like > device_pretty_name(dev), which some classes may implement somehow. > > What are your ideas about this problem? I lost track of where these file will appear. I was surprised with the location in the first proposal Looking at one of my systems we have: ls -l /sys/class/net/eth0/ total 0 -r--r--r-- 1 root root 4096 Sep 26 14:34 addr_assign_type -r--r--r-- 1 root root 4096 Sep 26 14:34 address -r--r--r-- 1 root root 4096 Sep 26 19:06 addr_len -r--r--r-- 1 root root 4096 Sep 26 19:06 broadcast ... phydev -> ../../mdio_bus/400d0000.ethernet-1/400d0000.ethernet-1:00 ... Will the LED class directory appear as a subdirectory of /sys/class/net/eth0/, or a subdirectory of ../../mdio_bus/400d0000.ethernet-1/400d0000.ethernet-1:00 or in /sys/class/leds? If they are in /sys/class/led, the name needs to be globally unique. That rules out using the interface name, which is not globally unique, it is only netns unique. If they are inside /sys/class/net/eth0, we don't need to worry about the name, we know which interface they belong to simply from the parent directory. We can then use "phy:yellow:activity". The same applies for "../../mdio_bus/400d0000.ethernet-1/400d0000.ethernet-1:00". The user can follow the symlink from /sys/class/net/eth0 to the phy directory to find the LEDs for a PHY. Andrew