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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 4FB26C4338F for ; Mon, 9 Aug 2021 12:06:28 +0000 (UTC) Received: from phobos.denx.de (phobos.denx.de [85.214.62.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 009A660F35 for ; Mon, 9 Aug 2021 12:06:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 009A660F35 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=denx.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.denx.de Received: from h2850616.stratoserver.net (localhost [IPv6:::1]) by phobos.denx.de (Postfix) with ESMTP id 9F2E081671; Mon, 9 Aug 2021 14:06:24 +0200 (CEST) Authentication-Results: phobos.denx.de; dmarc=none (p=none dis=none) header.from=denx.de Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=u-boot-bounces@lists.denx.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1628510784; bh=DU/sq+Ceu2vr4KsWg1qFvF+WggRVvUcZoCJI+w310D4=; h=From:To:Cc:Subject:Date:List-Id:List-Unsubscribe:List-Archive: List-Post:List-Help:List-Subscribe:From; b=AsYbDwzjYINfg0K4FX005HjjTM1dTTy4SRo3LU2aRVh+jnBbNpqAMQqd6aUnP/v4H hb0FsJaxVBBvcfxhlkJhgjUxdtCEmCVDGOSa8N0/w6XUfE42IGXZOny7eFohCRt3gX 5lJ4AArXRLWJvAig3kuu/wkQSjHQFkzerWMTHNWPmVyR8Y9lNXYxLk2D3p5ckY7DJP NGDtKPQfdkmhD12v8ZvCj10ExlLINbyO6P9EdC5jP27DBTgx/4a5PvDc7quV/j+cTD h+76uffc4PK15owByaQyYtQwrno7PZcBUEWTynHJ2D3EguWnRlqouVKUgyMqqx7Div +SmkWbtDgIlqA== Received: from tr.lan (ip-89-176-112-137.net.upcbroadband.cz [89.176.112.137]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id 4F43981269; Mon, 9 Aug 2021 14:06:23 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1628510783; bh=DU/sq+Ceu2vr4KsWg1qFvF+WggRVvUcZoCJI+w310D4=; h=From:To:Cc:Subject:Date:From; b=XlG9YLgyBMUZaxkBGnpcKzpgy/Kw5lEaBbSjFWrwlIqqLd1Qe1X4rnzTcHQ+VbikN xCi/MNeZc2AIxnW72OIIjy+vckvkUoxdSx6MTVougQqvw3hQjwSq4+LZ59VmHA184p uxgu5zvl5HrEWqM0PtvaG55W1VeBJoE0+Lx2bXkrP4lvUPsbdWtPJt+Q+8gicbuwjc HA8j+zVUdlZNrURgFt6Lw83CrOtJtziQk++UKR6eqkucP/otbQjgX+FeO/S7vEsLjD QXGrKXU7NsScUbz7W6vX4WSh+HH+Z/Z97wS6Wn6rl0BDSAGhLcNtCdn4wGRbAWdWau +qihqZiVoQMBQ== From: Marek Vasut To: u-boot@lists.denx.de Cc: Marek Vasut , Patrice Chotard , Patrick Delaunay Subject: [PATCH] ARM: dts: stm32: Reduce DHCOR SPI NOR frequency to 50 MHz Date: Mon, 9 Aug 2021 14:06:04 +0200 Message-Id: <20210809120604.154080-1-marex@denx.de> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: u-boot@lists.denx.de X-Mailman-Version: 2.1.34 Precedence: list List-Id: U-Boot discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: u-boot-bounces@lists.denx.de Sender: "U-Boot" X-Virus-Scanned: clamav-milter 0.103.2 at phobos.denx.de X-Virus-Status: Clean The SPI NOR is a bit further away from the SoC on DHCOR than on DHCOM, which causes additional signal delay. At 108 MHz, this delay triggers a sporadic issue where the first bit of RX data is not received by the QSPI controller. There are two options of addressing this problem, either by using the DLYB block to compensate the extra delay, or by reducing the QSPI bus clock frequency. The former requires calibration and that is overly complex for SPL, so opt for the second option. This incurs 20ms delay during boot, when SPL loads U-Boot to DRAM. Signed-off-by: Marek Vasut Cc: Patrice Chotard Cc: Patrick Delaunay --- arch/arm/dts/stm32mp15xx-dhcor-io3v3.dtsi | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/dts/stm32mp15xx-dhcor-io3v3.dtsi b/arch/arm/dts/stm32mp15xx-dhcor-io3v3.dtsi index 64299df8166..94cf80dbede 100644 --- a/arch/arm/dts/stm32mp15xx-dhcor-io3v3.dtsi +++ b/arch/arm/dts/stm32mp15xx-dhcor-io3v3.dtsi @@ -198,7 +198,7 @@ compatible = "jedec,spi-nor"; reg = <0>; spi-rx-bus-width = <4>; - spi-max-frequency = <108000000>; + spi-max-frequency = <50000000>; #address-cells = <1>; #size-cells = <1>; }; -- 2.30.2