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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 2DBD0C433F5 for ; Tue, 12 Apr 2022 18:58:22 +0000 (UTC) Received: from h2850616.stratoserver.net (localhost [IPv6:::1]) by phobos.denx.de (Postfix) with ESMTP id 163E6841B3; Tue, 12 Apr 2022 20:47:49 +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=1649789269; bh=hEqGuxnRUKX6QyiQjRC+ehZ7Mzb4wE46ELgUOmoYHsE=; h=From:To:Subject:In-reply-to:Date:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From; b=VxTO0NxGD0ZNTXclOTV/7l6SjtDX3nGKzMAY8ObiGOZAUefXq+IpvJLEt2Zs7k6Em gUpKbr4wtWPyV3M0608XTgK+1KBgbgMGQBbcyjmrpetkSd0IMYvMXyafI5AYYsgjaS U3SBtujqTY2H+bmZ9qqzBimhDRRoBpC4fzcj40zLdzDPgI9t/rt44Y4xrMP5denIqO OXbHQaOvJzEfAwxi7x0BCmMK9JqiIzuQ8HlSZAQi77YsGTePxb/mZqbakJdkRCJa9E CA+kAKC14Vu6CwrgdewpTCCMI2V53NeR6CxwHBnN5torArC91uUfHn+qaY6h3Xy/hC 8rAQSA8fzj0jA== Received: by phobos.denx.de (Postfix, from userid 109) id 985FF8408B; Tue, 12 Apr 2022 20:46:58 +0200 (CEST) Received: from mail-out.m-online.net (mail-out.m-online.net [212.18.0.9]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by phobos.denx.de (Postfix) with ESMTPS id 5065384010 for ; Tue, 12 Apr 2022 20:46:56 +0200 (CEST) Authentication-Results: phobos.denx.de; dmarc=none (p=none dis=none) header.from=denx.de Authentication-Results: phobos.denx.de; spf=fail smtp.mailfrom=sbabic@denx.de Received: from frontend01.mail.m-online.net (unknown [192.168.8.182]) by mail-out.m-online.net (Postfix) with ESMTP id 4KdF7h0ZFZz1qyJ7; Tue, 12 Apr 2022 20:46:56 +0200 (CEST) Received: from localhost (dynscan1.mnet-online.de [192.168.6.70]) by mail.m-online.net (Postfix) with ESMTP id 4KdF7h0T06z1qqkB; Tue, 12 Apr 2022 20:46:56 +0200 (CEST) X-Amavis-Alert: BAD HEADER SECTION, Missing required header field: "Date" Received: from mail.mnet-online.de ([192.168.8.182]) by localhost (dynscan1.mail.m-online.net [192.168.6.70]) (amavisd-new, port 10024) with ESMTP id GGOkTRtvt7WL; Tue, 12 Apr 2022 20:46:55 +0200 (CEST) Received: from papero (host-88-217-136-221.customer.m-online.net [88.217.136.221]) by mail.mnet-online.de (Postfix) with ESMTP; Tue, 12 Apr 2022 20:46:55 +0200 (CEST) From: sbabic@denx.de X-Patchwork-Submitter: Francesco Dolcini X-Patchwork-Id: 1613928 X-Patchwork-Delegate: sbabic@denx.de To: Francesco Dolcini ,u-boot@lists.denx.de Subject: [PATCH v1 2/2] mx6: ddr: Wait before issuing the first MRS cmd In-reply-to: <20220406115325.98086-3-francesco.dolcini@toradex.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit MIME-Version: 1.0 Message-Id: <20220412184658.985FF8408B@phobos.denx.de> Date: Tue, 12 Apr 2022 20:46:56 +0200 (CEST) X-BeenThere: u-boot@lists.denx.de X-Mailman-Version: 2.1.39 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 0.103.5 at phobos.denx.de X-Virus-Status: Clean > Wait 1ms before issuing the first MRS command to write DDR3 Mode > registers. > There is a requirement to wait a minimum time before issuing command to > the DDR3 device, according to the JEDEC standard this time is 500us > (after RESET_n is de-asserted until CKE becomes active) + tXPR (Reset > CKE Exit time, maximum value 360ns). > It seems that for some reason this is not enforced by the MMDC > controller. > Without this change we experienced random memory initialization failures > with about 2% boot failure rate on specific problematic boards, after > this change we were able to do more than 10.000 power-cycle without a > single failure. > Fixes: fe0f7f7842e1 ("mx6: add mmdc configuration for MX6Q/MX6DL") > Signed-off-by: Francesco Dolcini > Reviewed-by: Marek Vasut > Reviewed-by: Fabio Estevam Applied to u-boot-imx, master, thanks ! Best regards, Stefano Babic -- ===================================================================== DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic@denx.de =====================================================================