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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 C72B8C2D0C3 for ; Sat, 28 Dec 2019 00:33:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9FC4F20828 for ; Sat, 28 Dec 2019 00:33:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726502AbfL1Adu (ORCPT ); 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.