From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932971AbaJXQTg (ORCPT ); Fri, 24 Oct 2014 12:19:36 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:48745 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932247AbaJXQTd (ORCPT ); Fri, 24 Oct 2014 12:19:33 -0400 Date: Fri, 24 Oct 2014 09:19:19 -0700 From: Guenter Roeck To: Andrew Lunn Cc: Florian Fainelli , netdev , "David S. Miller" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 06/14] net: dsa: Add support for hardware monitoring Message-ID: <20141024161919.GA29600@roeck-us.net> References: <1414037002-25528-7-git-send-email-linux@roeck-us.net> <54488CE1.2000106@roeck-us.net> <20141023134706.GB25190@lunn.ch> <20141023162754.GA21343@roeck-us.net> <20141023165459.GE25190@lunn.ch> <20141023173847.GA22988@roeck-us.net> <20141023180357.GG25190@lunn.ch> <20141023184322.GA24281@roeck-us.net> <20141023195526.GH25190@lunn.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20141023195526.GH25190@lunn.ch> User-Agent: Mutt/1.5.21 (2010-09-15) X-Authenticated_sender: guenter@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-CTCH-PVer: 0000001 X-CTCH-Spam: Unknown X-CTCH-VOD: Unknown X-CTCH-Flags: 0 X-CTCH-RefID: str=0001.0A020209.544A7C14.02EC,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0 X-CTCH-Score: 0.000 X-CTCH-ScoreCust: 0.000 X-CTCH-Rules: C_4847, X-CTCH-SenderID: linux@roeck-us.net X-CTCH-SenderID-Flags: 0 X-CTCH-SenderID-TotalMessages: 5 X-CTCH-SenderID-TotalSpam: 0 X-CTCH-SenderID-TotalSuspected: 0 X-CTCH-SenderID-TotalConfirmed: 0 X-CTCH-SenderID-TotalBulk: 0 X-CTCH-SenderID-TotalVirus: 0 X-CTCH-SenderID-TotalRecipients: 0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: mailgid no entry from get_relayhosts_entry X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 23, 2014 at 09:55:26PM +0200, Andrew Lunn wrote: > On Thu, Oct 23, 2014 at 11:43:22AM -0700, Guenter Roeck wrote: > > On Thu, Oct 23, 2014 at 08:03:57PM +0200, Andrew Lunn wrote: > > > > No, I am not saying that. The hwmon device's parent device will tell, > > > > which is how it works for all other hwmon devices. > > > > > > O.K, so parent is important. > > > > > > > Not really. Again, the parent device provides that information. libsensors, > > > > which is the preferred way of accessing sensors information from user space, > > > > provides the parent device instance as part of the logical sensor device > > > > name. In this case, the names will end up being dsa-isa-0000, dsa-isa-0001, > > > > and so on. With your added tags it would be dsa.0.0-isa-0000, dsa.0.1-isa-0001, > > > > and so on. I don't see how this would add any value. > > > > > > isa is the name of the ethernet device? Why is it not eth0? Most > > > > isa is just an internal name made up by libsensors, and pretty much just > > indicates something like "neither i2c nor spi". It is mostly historic, > > but nowadays almost part of the ABI. It is made up by user space, > > based on the parent device type, not by the kernel. > > So for DSA, since it is not i2c or spi, the parent is actually > irrelevant, because libsensor ignores it and says "IsSomethingAlien". > So the name alone needs to identify it. > > > You have convinced me that 'dsa' as hwmon attribute name is insufficient, > > so let's see what we have. > > > > - the parent network device in dst->master_netdev > > - the dsa device in 'parent' > > - the host device in host_dev > > - the switch index in 'index' > > > > First question is what should be the parent device. > > Does it even matter, given the observation above? I would probably go > for dsa, since as you said, the Ethernet device may have a temperature > sensor of its own. DSA is a virtual device... > > > Second is what to choose for the hwmon device 'name' attribute. > > 'dsa' is not sufficient, but what to choose instead ? dsa.X or dsa_X, > > where X is the switch index ? At this point I am open to suggestions. > > Note that we can not use the name returned from the switch probe > > functions as it may contain spaces and other invalid characters. > > Including the ethernet device name (eg as in eth0_dsa_0) may also be > > problematic if it can contain '-', which is illegal for hwmon devices. > > Does hwmon offer a function to sanitise a string? > > The switch index definitely should be used and i would probably > combine that with a sanitised version of the ethernet device name and > "dsa". > Here is another naming option: em1dsa0-virtual-0 Adapter: Virtual device temp1: +52.0°C (high = +100.0°C) I think I'll go with that one. I get it by not specifying a parent device when registering with the hwmon subsystem. It is kind of similar to the thermal sensor data reported through acpi. acpitz-virtual-0 Adapter: Virtual device temp1: +52.0°C (crit = +111.0°C) temp2: +52.0°C (crit = +111.0°C) Guenter