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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 87D92C54E8B for ; Tue, 12 May 2020 06:49:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 64A9F20769 for ; Tue, 12 May 2020 06:49:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728904AbgELGtK (ORCPT ); Tue, 12 May 2020 02:49:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50662 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1725823AbgELGtG (ORCPT ); Tue, 12 May 2020 02:49:06 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8FCD0C061A0C for ; Mon, 11 May 2020 23:49:06 -0700 (PDT) Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jYOir-00034q-1r; Tue, 12 May 2020 08:49:01 +0200 Received: from ore by dude.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1jYOio-00038O-GG; Tue, 12 May 2020 08:48:58 +0200 Date: Tue, 12 May 2020 08:48:58 +0200 From: Oleksij Rempel To: Michal Kubecek Cc: Marek Vasut , Andrew Lunn , Florian Fainelli , Jonathan Corbet , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Russell King , mkl@pengutronix.de, kernel@pengutronix.de, David Jander , Jakub Kicinski , Christian Herber , "David S. Miller" , Heiner Kallweit Subject: Re: signal quality and cable diagnostic Message-ID: <20200512064858.GA16536@pengutronix.de> References: <20200511141310.GA2543@pengutronix.de> <20200511145926.GC8503@lion.mk-sys.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200511145926.GC8503@lion.mk-sys.cz> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-IRC: #ptxdist @freenode X-Accept-Language: de,en X-Accept-Content-Type: text/plain X-Uptime: 07:14:20 up 243 days, 18:02, 450 users, load average: 0.57, 0.51, 0.53 User-Agent: Mutt/1.10.1 (2018-07-13) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 11, 2020 at 04:59:26PM +0200, Michal Kubecek wrote: > On Mon, May 11, 2020 at 04:13:10PM +0200, Oleksij Rempel wrote: > > > > I continue to work on TJA11xx PHY and need to export some additional > > cable diagnostic/link stability information: Signal Quality Index (SQI). > > The PHY data sheet describes it as following [1]: > > ================================================================================ > > 6.10.3 Link stability > > > > The signal-to-noise ratio is the parameter used to estimate link > > stability. The PMA Receive function monitors the signal-to-noise ratio > > continuously. Once the signal-to-noise ratio falls below a configurable > > threshold (SQI_FAILLIMIT), the link status is set to FAIL and > > communication is interrupted. The TJA1100 allows for adjusting the > > sensitivity of the PMA Receive function by configuring this threshold. > > The microcontroller can always check the current value of the > > signal-to-noise ratio via the SMI, allowing it to track a possible > > degradation in link stability. > > ================================================================================ > > > > Since this functionality is present at least on TJA11xx PHYs and > > mandatory according to Open Alliance[2], I hope this functionality is > > present on other 100/1000Base-T1 PHYs. So may be some common abstraction > > is possible. What would be the best place to provide it for the user > > space? According to the [2] SQI, is the part of Dynamic Channel Quality > > (DCQ) together with Mean Square Error (MSE) and Peak MSE value (pMSE). > > IIUC these would be read-only parameters describing current state of the > link which can be queried at any time. If this is the case, adding them > as attributes to ETHTOOL_MSG_LINKSTATE_GET_REPLY message seems most > fitting. ok > As for getting / setting the threshold, perhaps ETHTOOL_MSG_LINKINFO_GET > and ETHTOOL_MSG_LINKINFO_SET. Unless you expect more configurable > parameters like this in which case we may want to consider adding new > request type (e.g. link params or link management). Currently in my short term todo are: - SQI - PHY undervoltage - PHY overtemerature So far, I have no idea for PHY health diagnostic. If we consider at least the mandatory properties listed in the opensig, then we would get following list: - DCQ (dynamic channel group) - SQI (Signal Quality Index) - HDD (Harness defect detection group) - OS (Open/Short detection) ----------------- implemented, cable test request. - LQ (Link Quality) - LTT (Link-training time. The time of the last link training) - LFL (Link Failures and Losses. Number of link losses since the last power cycle) - COM (communication ready) ----------------- implemented? - POL (Polarity detection & correction) - DET (Polarity detect) I personally would add RE_ERR counter in this list as well. Probably some one, soon or later, will try to implement them. If I see it correctly, some of this properties are already implemented within other request types. Is it worth to a add a new request type for the rest of them? Regards, Oleksij -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |