From patchwork Wed Jul 17 12:57:39 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Horman X-Patchwork-Id: 11047821 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3CED714DB for ; Wed, 17 Jul 2019 12:58:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2AB9E205A9 for ; Wed, 17 Jul 2019 12:58:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 11B5D28704; Wed, 17 Jul 2019 12:58:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id DC1CF2844B for ; Wed, 17 Jul 2019 12:58:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Owner; bh=0pto/L3L6CbRuHl6LMFT4hxwXl3B33wPasR72DbcYy8=; b=twI Yr4oI+iSq+QC916RHfaNqmMz/OIbJD2CG+0oizRh6kt1+93Igt+tHiW5N3osMWV6MwK2WUd3RgrYZ 2waW290j5PqmABDb4zsuiuewL4q11bogZtPDPXNS22OUsM46/gLYQmhNA+WgYiJI06zP4xBYzEiIr l8AtAcyLNGtdGg8v5cFA5ZVpE6RgqMwhSH6pikXFgenQVmvoFnh5El+qEiETRsTTuPl2HhY3kilqN k/HrEpc8N5Se6QQBICISMARuJEIh+sugrMymYhECaArwuVYRWm9v2vZ4gzU7yiRVGGwxl9Xe1/ALD 8zpmzOFieFmVBEOjA+elMeLhhThUCog==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hnjVL-0002T6-Ev; Wed, 17 Jul 2019 12:57:55 +0000 Received: from kirsty.vergenet.net ([202.4.237.240]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hnjVI-0002Sk-6L for linux-arm-kernel@lists.infradead.org; Wed, 17 Jul 2019 12:57:53 +0000 Received: from reginn.horms.nl (watermunt.horms.nl [80.127.179.77]) by kirsty.vergenet.net (Postfix) with ESMTPA id ABF7525AD5F; Wed, 17 Jul 2019 22:57:46 +1000 (AEST) Received: by reginn.horms.nl (Postfix, from userid 7100) id B55B8940270; Wed, 17 Jul 2019 14:57:44 +0200 (CEST) From: Simon Horman To: Geert Uytterhoeven , linux-renesas-soc@vger.kernel.org Subject: [PATCH/RFC repost] arm64: dts: renesas: ebisu, draak: Limit EtherAVB to 100Mbps Date: Wed, 17 Jul 2019 14:57:39 +0200 Message-Id: <20190717125739.21450-1-horms+renesas@verge.net.au> X-Mailer: git-send-email 2.11.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190717_055752_391116_5ED43D43 X-CRM114-Status: UNSURE ( 9.92 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Andrew Lunn , Simon Horman , Magnus Damm , linux-arm-kernel@lists.infradead.org, Wolfram Sang MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP * According to the R-Car Gen3 Hardware Manual Errata for Rev 1.00 of August 24, 2018, the TX clock internal delay mode isn't supported on R-Car E3 (r8a77990) and D3 (r8a77995). * TX clock internal delay mode is required for reliable 1Gbps communication using the KSZ9031RNX phy present on the Ebisu and Draak boards. Thus, the E3 based Ebisu and D3 based Draak boards reliably use 1Gbps and the speed should be limited to 100Mbps. Based on work by Kazuya Mizuguchi. Signed-off-by: Simon Horman --- This is a repost of this change. In earlier review Andrew Lunn suggested that we may be able to take a different approach to this problem by using delays provided by the KSZ9031RNX PHY. In particular MMD address 2h, Register 8h - RGMII Clock Pad Skew. I have consulted with Renesas regarding this suggestion, however, unfortunately it appears that the delays provided by this solution would be insufficient to allow for reliable 1Gbps communication. At this point I believe the safest option is to apply this patch. --- arch/arm64/boot/dts/renesas/r8a77990-ebisu.dts | 1 + arch/arm64/boot/dts/renesas/r8a77995-draak.dts | 1 + 2 files changed, 2 insertions(+) diff --git a/arch/arm64/boot/dts/renesas/r8a77990-ebisu.dts b/arch/arm64/boot/dts/renesas/r8a77990-ebisu.dts index 83fc13ac3fa1..3d3d6d438a05 100644 --- a/arch/arm64/boot/dts/renesas/r8a77990-ebisu.dts +++ b/arch/arm64/boot/dts/renesas/r8a77990-ebisu.dts @@ -271,6 +271,7 @@ interrupt-parent = <&gpio2>; interrupts = <21 IRQ_TYPE_LEVEL_LOW>; reset-gpios = <&gpio1 20 GPIO_ACTIVE_LOW>; + max-speed = <100>; }; }; diff --git a/arch/arm64/boot/dts/renesas/r8a77995-draak.dts b/arch/arm64/boot/dts/renesas/r8a77995-draak.dts index 0711170b26b1..eb153323ed13 100644 --- a/arch/arm64/boot/dts/renesas/r8a77995-draak.dts +++ b/arch/arm64/boot/dts/renesas/r8a77995-draak.dts @@ -175,6 +175,7 @@ reg = <0>; interrupt-parent = <&gpio5>; interrupts = <19 IRQ_TYPE_LEVEL_LOW>; + max-speed = <100>; }; };