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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D9DCECAAD6 for ; Fri, 26 Aug 2022 19:51:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344734AbiHZTvp (ORCPT ); Fri, 26 Aug 2022 15:51:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33942 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237423AbiHZTvn (ORCPT ); Fri, 26 Aug 2022 15:51:43 -0400 Received: from vps0.lunn.ch (vps0.lunn.ch [185.16.172.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0012E68D7; Fri, 26 Aug 2022 12:51:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Disposition:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:From:Sender:Reply-To:Subject: Date:Message-ID:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Content-Disposition:In-Reply-To:References; bh=WHWgyZwOYt0ERDM3VLaqXQ19lWQ7CWa684W/FQaw+UA=; b=r6IG98sZlE9Jq1u//TbhWfAGbV aXin1hNGByAMXp6XahdFfDu+h6yyN66fEXYtMd/teltMY2dy908m+0bU6HMse/2XwBQZJEGD+mUjq 3InVH3NuQnhnK0xcUdJrVUbAWva1OfU+z8QX7o11OszBGII26gVk5X/w2rIMu26ijWUQ=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1oRfMX-00Eidz-OJ; Fri, 26 Aug 2022 21:51:29 +0200 Date: Fri, 26 Aug 2022 21:51:29 +0200 From: Andrew Lunn To: Oleksij Rempel Cc: Michael Walle , Divya.Koppera@microchip.com, UNGLinuxDriver@microchip.com, davem@davemloft.net, edumazet@google.com, hkallweit1@gmail.com, kuba@kernel.org, linux-kernel@vger.kernel.org, linux@armlinux.org.uk, netdev@vger.kernel.org, pabeni@redhat.com Subject: Re: [PATCH net-next] net: phy: micrel: Adding SQI support for lan8814 phy Message-ID: References: <20220825080549.9444-1-Divya.Koppera@microchip.com> <20220826084249.1031557-1-michael@walle.cc> <421712ea840fbe5edffcae4a6cb08150@walle.cc> <20220826095429.GE2116@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220826095429.GE2116@pengutronix.de> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org > > > In lan8814 phy only channel 0 is used for 100base-tx. So returning SQI > > > value for channel 0. > > > > What if the other pairs are bad? Maybe Oleksij has an opinion here. > > > > Also 100baseTX (and 10baseT) has two pairs, one for transmitting and one > > for receiving. I guess you meassure the SQI on the receiving side. So is > > channel 0 correct here? > > > > Again this is the first time I hear about SQI but it puzzles me that > > it only evaluate one pair in this case. So as a user who reads this > > SQI might be misleaded. > > Wow! I was so possessed with one-pair networks, that forgot to image > that there is 1000Base-T with more then one pairs :D > > Yes, your are right. We wont to have readings from all RX channels and > be able to export them to the user space. In fact, if i see it > correctly, the LAN8814_DCQ_CTRL_CHANNEL_MASK value should be synced with > the MDI-X state. Otherwise we will be reading TX channels. I don't know if i should trust the datasheet i found, but it suggests the register in MMD device 1 space has a field to indicate which cable pair should be measured. So for 1000Base-T all pairs are both Rx and Tx, so i would expect 4 values are returned. That then might need an uAPI extension, if you were focused on T1 :-) Andrew