From patchwork Thu Mar 7 08:41:56 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Muellner X-Patchwork-Id: 10842425 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 D21891669 for ; Thu, 7 Mar 2019 08:43:30 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BCFC02E065 for ; Thu, 7 Mar 2019 08:43:30 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B05282E081; Thu, 7 Mar 2019 08:43:30 +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 68A2D2E065 for ; Thu, 7 Mar 2019 08:43:30 +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:References: In-Reply-To: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:List-Owner; bh=DGPgAahbykTqwYRKZmOAygF3rbd1DTAetJIk5vyaDVo=; b=T4l8kNd4hQTPa6sM21aOif7FOt Bzmw65273mkxS75TJV9CE0XY0qlkGnX03zft80h59b4XBlX5k1HGLPRVSw6Pu1eSCqi6PPvHWPZiQ O6DzKtLdOul+EYwj/osA30wdrfownnPxbJq5yhpnqv8qEEqUPIus8UXyzBM+yNnkDMP96/DssiTrG GTKCyI+wyrzkneKObnolz3WANqbS9fKth/AFUiEFFBW09Hv2y7qegWF4wrglj73KoePZk5hMT1vn7 BP9qnUa4ueHM9eo4/A257VzgUAx/DMyM3wGj2wu638u0/+6/zftTnmWt1E4wGtQGmCA+v4PncglVy prVNeMCA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1h1ocg-0004WY-IB; Thu, 07 Mar 2019 08:43:26 +0000 Received: from vegas.theobroma-systems.com ([144.76.126.164] helo=mail.theobroma-systems.com) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1h1ocK-0004Am-Rt; Thu, 07 Mar 2019 08:43:18 +0000 Received: from ip092042140082.rev.nessus.at ([92.42.140.82]:54490 helo=purcell.lan) by mail.theobroma-systems.com with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.80) (envelope-from ) id 1h1obY-000810-Qy; Thu, 07 Mar 2019 09:42:16 +0100 From: Christoph Muellner To: robh+dt@kernel.org, mark.rutland@arm.com, heiko@sntech.de, shawn.lin@rock-chips.com Subject: [PATCH v2 4/4] arm64: dts: rockchip: Decrease emmc-phy's drive impedance on rk3399-puma Date: Thu, 7 Mar 2019 09:41:56 +0100 Message-Id: <20190307084159.25236-4-christoph.muellner@theobroma-systems.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190307084159.25236-1-christoph.muellner@theobroma-systems.com> References: <20190307084159.25236-1-christoph.muellner@theobroma-systems.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190307_004305_799267_5D0DE267 X-CRM114-Status: UNSURE ( 9.33 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-rockchip@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Upstream kernel work for Rockchip platforms List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, Matthias Brugger , Lin Huang , Viresh Kumar , Brian Norris , Douglas Anderson , Vicente Bergas , Kishon Vijay Abraham I , linux-rockchip@lists.infradead.org, Jeffy Chen , Tony Xie , Klaus Goger , linux-arm-kernel@lists.infradead.org, Enric Balletbo i Serra , Randy Li , Philipp Tomsich , Ezequiel Garcia , linux-kernel@vger.kernel.org, Christoph Muellner MIME-Version: 1.0 Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+patchwork-linux-rockchip=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP The RK3399-Q7 (Puma) requires 33 Ohm drive strength to ensure signal integrity at HS-400 (200MHz clock, DDR signalling). A repeated EMC testing run validates that this increase does not negatively impact EMC compliance (emissions have ample distance to the regulatory limits). Signed-off-by: Christoph Muellner Signed-off-by: Philipp Tomsich Tested-by: Jakob Unterwurzacher Tested-by: Klaus Goger --- arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi b/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi index 0130b9f98c9d..4f75bb6b2f14 100644 --- a/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi +++ b/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi @@ -146,6 +146,7 @@ &emmc_phy { status = "okay"; + drive-impedance-ohm = <33>; }; &gmac {