From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f54.google.com (mail-wm1-f54.google.com [209.85.128.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CA6C921B8EC; Fri, 7 Mar 2025 14:22:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.54 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741357378; cv=none; b=cQmQFPKSJg5An6bXC3saVsc1pRUNfXD2NOoIzE+9i6368zdjG2ZQZMivQB5afSBZW7MiPO8CQSF3d0JDKJ+aMk3/6uH4gR/Cog9ljnJa3gEZhZyApsPenL6zgOjIzk2x1BTrNLDBAhSg2E0wunui3v8tg6f4+/YZyqwSx8AhjAU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741357378; c=relaxed/simple; bh=GvUKH5oJnoRKKMs29BXEgbZczyorqGQcyFWXcpVYfZc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=thRt67sA+cmwJ2CD9e6Jn3Nfr3vZBbJIaYF62iqcmy74opnke8LFptwqEZVZL39sacMKrQjpQv7icl/AWS5IRp8EZdIr7pl+l7wmsWMgHZLWXHJyI3sY45iMW0Q2qU26XISmwHdq7PUYLwpaf9rNzphr+Mg9sUAB9wV9DHTSnw0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=bj1vUZRV; arc=none smtp.client-ip=209.85.128.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bj1vUZRV" Received: by mail-wm1-f54.google.com with SMTP id 5b1f17b1804b1-43bc4b16135so11396445e9.1; Fri, 07 Mar 2025 06:22:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1741357375; x=1741962175; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=PejxjOLcOPCBsN9OKYEARibmDmaIRCji7dqrz9O8QL0=; b=bj1vUZRVP0olf6N/2u9keEr5PhnHCnZJke8JRdb0+DqU9cNbbUYIXUXUu5wI4l8Nw5 tTl5mMKfhcvDtW/viec0DvBizZampfd6SVUXaVfpSpS3DeqJyTMA6X/MAHBi0TYZnMzd hVUsH6LM2k7fbz/DEdVYJR00mel+hwkFn4AMYZEJ4vViqgmnjKNVTsg9NXLuIgDNGwwD 5ShHhEvjlMKSboidXXUF4LdwPQaMQtj9Gzt7iLxwJxSw4Qj9jVx+9VovXx8l8CZWGfih Y0IeyyUaJb3QUp4Z/J5J7oB/KS+W7OZ0r2BaEoH1ekoZNZ0Z4PfZtt1FEMJh00+MA5O3 riew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1741357375; x=1741962175; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=PejxjOLcOPCBsN9OKYEARibmDmaIRCji7dqrz9O8QL0=; b=jkDNp5anGxzkIHXjmhC1R595RAJmhcnXpMmqtSthVBRjycHgSpGJj2JhFIBm6EYcdM MG+ARkSTL0ibwen0oW8dZOrxxrwPbO2G0VNBPOkYLcpXVFBYqLgzSzZc/ymKgZ16YV5K EDwmRnnQMHr6EiCkwG7hF51JD08TTqZKfnnJ9tw+E1UA8PrIgTzvEbkp5u8leMkqlTBX Z2yKYbCBwGYve3hYbfeiG9wwutO2TBKpZ9HpEFo+GO5rS9IdYOs7RdJ8GbfbBszOc4LA in8ZbsXihonrRbd/6EgPpjzBgfVodFtim3453RiUap8uXuhNhn3xWXO+xlT29bMG767X m29w== X-Forwarded-Encrypted: i=1; AJvYcCVGZSlwzkM8uPG3YRUpFw+RUqvJY7k3hXF+dd48mkRf7sWzDTRl9ckGUZ3EQDQW0xaRrqAtcYIJnzYF0kdt@vger.kernel.org, AJvYcCWLyuMs3Pyp+mWYax32UUjw5PD//PykfkPsQTfvhUS6JV0h8EZoCpPOB2ANlwDDTdlSQp7NZVD9hcxu@vger.kernel.org, AJvYcCWQEQpipsnXZhC8WBAjHqrZ5j+xRmLrybAFX952vr1Ff8lx8U4NZV6HLgGsXpld9Ln3Kz+JdA/C@vger.kernel.org X-Gm-Message-State: AOJu0YzVIXKYHwMWvGysPLQcYL3lT81bX2eOFPSyRNzpTEXGnoVeWYTZ oS0D4t6ooW9lKTVZR4etWaYTgO2rX9uIVT0snB5j96IhgMt82aE8 X-Gm-Gg: ASbGncvcP+8tkuqVdfHorLsLb9bUWeygWvwj0PnTPHiD4AHc+l2XTpOMyISFq6RZ3Do BccJUbyFKbgbQpEg5ieeKXycYOt8AiGVi2AsyB3gfsy2lo5vXVLG6w+yT+2X58deVbd0rX2FtNr Ip2THlUuo8kaCu54I4qGJOaW4w1J+HuV71Q1FCWDXAugmIwvCYGhGLE2+yxzsWIC1kTX4vM+5En muifxqw7YpohdNMBvZjGtsWlyv7mS3tHEswYCrJmGoZlJlHnwzjKaoZftqofYXb/vS9ZZdFLpFW tB9v6KgbU8t4jNiHWlgNVdAMFYuZxbaW3FbwAQcXOfk= X-Google-Smtp-Source: AGHT+IHRSH7+mnghk5+K6OY1NH52/2MRSnfqJmNP3IiaQH5tQ5r0hWfDAhatgkUrfGbEuoehDRIFqg== X-Received: by 2002:a05:600c:190d:b0:439:99ab:6178 with SMTP id 5b1f17b1804b1-43c601cf229mr24881215e9.6.1741357374842; Fri, 07 Mar 2025 06:22:54 -0800 (PST) Received: from legfed1 ([2a00:79c0:614:ea00:1ebe:eb51:3a97:3b47]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-43bdd948c1bsm51706755e9.36.2025.03.07.06.22.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Mar 2025 06:22:54 -0800 (PST) Date: Fri, 7 Mar 2025 15:22:52 +0100 From: Dimitri Fedrau To: Andrew Lunn Cc: dimitri.fedrau@liebherr.com, Heiner Kallweit , Russell King , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Florian Fainelli , netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next 0/3] net: phy: dp83822: Add support for changing the MAC series termination Message-ID: <20250307142252.GA2326148@legfed1> References: <20250307-dp83822-mac-impedance-v1-0-bdd85a759b45@liebherr.com> <6aee57d3-8657-44d6-ac21-9f443ca0924e@lunn.ch> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6aee57d3-8657-44d6-ac21-9f443ca0924e@lunn.ch> Am Fri, Mar 07, 2025 at 02:39:32PM +0100 schrieb Andrew Lunn: > On Fri, Mar 07, 2025 at 11:30:00AM +0100, Dimitri Fedrau via B4 Relay wrote: > > The dp83822 provides the possibility to set the resistance value of the > > the MAC series termination. Modifying the resistance to an appropriate > > value can reduce signal reflections and therefore improve signal quality. > > I have some dumb questions.... > > By referring to MAC from the perspective of the PHY, do you mean the > termination of the bus between the MAC and the PHY? The SGMII SERDES, > or RGMII? > - Yes, the perspective is from the PHY. - Yes, but only the outputs towards the MAC. Resistors can be saved on the PCB when they are integrated into the PHY. - The PHY is able to operate with RGMII, RMII and MII. Should I rename then "mac-series-termination-ohms" to "output-mac-series-termination-ohms" or similar ? > I'm assuming the terminology is direct from the datasheet of the PHY? > But since this is a bit of a niche area, no other PHY driver currently > supports anythings like this, the terminology is not well known. So it > would be good to expand the description, to make it really clear what > you are talking about, so if anybody else wants to add the same > feature, they make use of the property, not add a new property. The datasheet calls it MAC impedance control, that is what someone might want to achieve when selecting the proper resistance value. I named it "mac-series-termination-ohms" instead to make sure what is done to achieve impedance matching. Should I add the proper description in the bindings ? Description of the properties are somehow short. However will expand the description. Best regards, Dimitri Fedrau