Received: by 2002:a25:8b91:0:0:0:0:0 with SMTP id j17csp11553719ybl; Fri, 27 Dec 2019 16:34:47 -0800 (PST) X-Google-Smtp-Source: APXvYqwWs5GX00akvpZinJd3GzYqBmEdLDMRCnxH/LY55XmI9F3r0PSvZHh54I/LOGV7HsxAuwjz X-Received: by 2002:a9d:6857:: with SMTP id c23mr45385306oto.351.1577493287639; Fri, 27 Dec 2019 16:34:47 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1577493287; cv=none; d=google.com; s=arc-20160816; b=LcpulcIYnm5pnCLnGDgKoa0Fd+4haOmmgZeVzbzc5R3XULRMphXCoI7j4Q3TGmdBXU UxXdUj6uSl2UKJ8GTckDeBkx4yVjzf2q5HmG6HhSJpRZlIN+zsbr/fL1gGIwkSKSD2hm uHjTUpiqY5hV4m0M2YhuGZ/TwfZKXctWLqdEwWSWC0aXEcV9TCj4L3Ic0N4aoBjx33Ko sflt2yBZJTSX5V/MDvMT73TUKmxWZUklsxI5w+NrbkNOE5r5cH76eNBIdSftDLzbOhGP Q6SE+XlUlySRbiVdjBv2p1FnDmK0DF4pqtr7aCm0hsTSo/VU+5VnnPA53ov6PC9ES9OY E5Hw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :references:in-reply-to:from:subject:cc:to:message-id:date; bh=YE8eK+F0pkwSBU7ygnyMrTa7HLuXFSgRLEhlW/QojGs=; b=DxLS6EKG9sV1ur/55zDz0KCPWbcCxcnForG5E1dKe18aeNs+6iDJqH4MoY75iqrr8V aebKXdrlDXvEdlkOTepG37psZ2gmd5uOvy22rjOUlVeEuU5eVz6K1DatxbW4jS8hnQlj FlrYTaqCgHzxyeX6NKZKKYbMEOChbqRjUKfZJrkcF9Zo434AzserZXqbjfgi5BQy3R6z HpDxiRohw8exyEB1ygicPt3y6Zho1hR6LZE8/01tkte6Dhx1KCkkqkiIJx1bZkpZuyoI rwX77cnKMcqKrqZAJ9U8MUZBTc/z7jJiWb/Xj6+2cFYkMsSpesFLF+UqnAEVn/Ywvjdc Axsg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id t20si18722363otr.64.2019.12.27.16.34.36; Fri, 27 Dec 2019 16:34:47 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726409AbfL1Adu (ORCPT + 99 others); Fri, 27 Dec 2019 19:33:50 -0500 Received: from shards.monkeyblade.net ([23.128.96.9]:53752 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725306AbfL1Adu (ORCPT ); Fri, 27 Dec 2019 19:33:50 -0500 Received: from localhost (unknown [IPv6:2601:601:9f00:1c3::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 39CAE154D1158; Fri, 27 Dec 2019 16:33:49 -0800 (PST) Date: Fri, 27 Dec 2019 16:33:48 -0800 (PST) Message-Id: <20191227.163348.1668601477335834984.davem@davemloft.net> To: martin.blumenstingl@googlemail.com Cc: linux-amlogic@lists.infradead.org, netdev@vger.kernel.org, khilman@baylibre.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, balbes-150@yandex.ru, ingrassia@epigenesys.com, jbrunet@baylibre.com, linus.luessing@c0d3.blue Subject: Re: [PATCH 0/3] Meson8b/8m2: Ethernet RGMII TX delay fixes From: David Miller In-Reply-To: <20191225005655.1502037-1-martin.blumenstingl@googlemail.com> References: <20191225005655.1502037-1-martin.blumenstingl@googlemail.com> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Fri, 27 Dec 2019 16:33:49 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Martin Blumenstingl Date: Wed, 25 Dec 2019 01:56:52 +0100 > The Ethernet TX performance has been historically bad on Meson8b and > Meson8m2 SoCs because high packet loss was seen. Today I (presumably) > found out why this is: the input clock (which feeds the RGMII TX clock) > has to be at least 4 times 125MHz. With the fixed "divide by 2" in the > clock tree this means that m250_div needs to be at least 2. ... It looks there needs to be more discussion on this series, please respin once the discussions are resolved. Thank you.