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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 731EFC433F5 for ; Mon, 13 Dec 2021 08:44:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=jrijfdL4OiV5nzrexsPRLTl6YyBO92dPYiHLUNScZCU=; b=HD279p6r6wgjkJ XRoyISTfTx4Lzya0nsdABfvSsrNRdXPS88sIN0W+3GEy55deF056/2JARMMY9uxdZ8s51QBQ1l1Yq IIKdGTrRgnj6p3N1/yKAq9KDhvkDi+eF29vj6NaldQjmeNjhWQ6qAmZSC2Jl5a5XzDaeHWgxOviyV EaVsNdO3PaeGRIhgPHzvt+j2Tvve16nYWix62tHEdeZcp5NNqwyf1VFmgMYiKzG/yi5U7mlchLcKp g8KyeXtZzDaT31nHNTnn2t/Rt892s25wIw4U6tFtFhlDKE583b7EOoUEzl5gvsFHBW7ilqTn5KcZ1 f91uOwFvdaWduzYMvrQA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mwgvM-008LAC-42; Mon, 13 Dec 2021 08:43:08 +0000 Received: from honk.sigxcpu.org ([24.134.29.49]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mwgut-008KuM-K4 for linux-arm-kernel@lists.infradead.org; Mon, 13 Dec 2021 08:42:41 +0000 Received: from localhost (localhost [127.0.0.1]) by honk.sigxcpu.org (Postfix) with ESMTP id 36392FB04; Mon, 13 Dec 2021 09:34:21 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at honk.sigxcpu.org Received: from honk.sigxcpu.org ([127.0.0.1]) by localhost (honk.sigxcpu.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id h6rKu9WI1p25; Mon, 13 Dec 2021 09:34:20 +0100 (CET) Date: Mon, 13 Dec 2021 09:34:18 +0100 From: Guido =?iso-8859-1?Q?G=FCnther?= To: Lucas Stach Cc: Shawn Guo , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , Martin Kepplinger , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] arm64: dts: imx8mq: disable DDRC node by default Message-ID: References: <20211212191541.2148178-1-dev@lynxeye.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20211212191541.2148178-1-dev@lynxeye.de> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211213_004239_855392_DDBF186B X-CRM114-Status: GOOD ( 18.61 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi, On Sun, Dec 12, 2021 at 08:15:41PM +0100, Lucas Stach wrote: > Without a OPP table or a downstream TF-A running on the system the DDRC w= ill > fail to probe, as it has no means to scale the DRAM frequency in that cas= e. > This however will block the bus scaling driver to come up and this in turn > prevents other devices that hook into the interconnect from probing. > = > If the DDRC is disabled, the interconnect driver will simply ignore it. As > most systems don't want to scale the DRAM frequency, disable the node by > default and only enable it on the systems that actually uses this > capability and provides a valid OPP table in the DT. > = > Signed-off-by: Lucas Stach > --- > arch/arm64/boot/dts/freescale/imx8mq-evk.dts | 1 + > arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi | 1 + > arch/arm64/boot/dts/freescale/imx8mq.dtsi | 1 + > 3 files changed, 3 insertions(+) > = > diff --git a/arch/arm64/boot/dts/freescale/imx8mq-evk.dts b/arch/arm64/bo= ot/dts/freescale/imx8mq-evk.dts > index b83df77195ec..e989a9e450ed 100644 > --- a/arch/arm64/boot/dts/freescale/imx8mq-evk.dts > +++ b/arch/arm64/boot/dts/freescale/imx8mq-evk.dts > @@ -122,6 +122,7 @@ &A53_3 { > }; > = > &ddrc { > + status =3D "okay"; > operating-points-v2 =3D <&ddrc_opp_table>; > = > ddrc_opp_table: opp-table { > diff --git a/arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi b/arch/arm= 64/boot/dts/freescale/imx8mq-librem5.dtsi > index 60d47c71499b..5c0e98c36f94 100644 > --- a/arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi > +++ b/arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi > @@ -238,6 +238,7 @@ &A53_3 { > }; > = > &ddrc { > + status =3D "okay"; > operating-points-v2 =3D <&ddrc_opp_table>; > = > ddrc_opp_table: opp-table { > diff --git a/arch/arm64/boot/dts/freescale/imx8mq.dtsi b/arch/arm64/boot/= dts/freescale/imx8mq.dtsi > index 972766b67a15..f5af9765e239 100644 > --- a/arch/arm64/boot/dts/freescale/imx8mq.dtsi > +++ b/arch/arm64/boot/dts/freescale/imx8mq.dtsi > @@ -1554,6 +1554,7 @@ ddrc: memory-controller@3d400000 { > <&clk IMX8MQ_DRAM_PLL_OUT>, > <&clk IMX8MQ_CLK_DRAM_ALT>, > <&clk IMX8MQ_CLK_DRAM_APB>; > + status =3D "disabled"; > }; > = > ddr-pmu@3d800000 { Reviewed-by: Guido G=FCnther Cheers, -- Guido > -- = > 2.31.1 > = _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel