From patchwork Thu Mar 17 12:45:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 552540 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AC187C4332F for ; Thu, 17 Mar 2022 12:54:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234310AbiCQMzx (ORCPT ); Thu, 17 Mar 2022 08:55:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38756 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234881AbiCQMx7 (ORCPT ); Thu, 17 Mar 2022 08:53:59 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 350461F0828; Thu, 17 Mar 2022 05:52:00 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id E96B5B81E01; Thu, 17 Mar 2022 12:51:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 311CDC340E9; Thu, 17 Mar 2022 12:51:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1647521517; bh=DPdfF6q9H15BXcu0xyHzF22kFQv23DsT8xa/YMq2E1I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KesRhouOAEDzayQww068SyEF8BkpFLpLTMmYPF6zvxr7Y3tJem4lwRP0Kinra1XrM hjXUo1mFvge+FZMCNugoz45FCcoxZBVEd9lkZfkCsg5dUNgfERWR/yQ+1nUFGeqoIF Qv2RZGiQer9biHL2M06aygcB1Zn2TQkdaICrlhfE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Quentin Schulz , Jakob Unterwurzacher , Quentin Schulz , Heiko Stuebner , Sasha Levin Subject: [PATCH 5.15 05/25] arm64: dts: rockchip: fix rk3399-puma eMMC HS400 signal integrity Date: Thu, 17 Mar 2022 13:45:52 +0100 Message-Id: <20220317124526.464713265@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220317124526.308079100@linuxfoundation.org> References: <20220317124526.308079100@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jakob Unterwurzacher [ Upstream commit 62966cbdda8a92f82d966a45aa671e788b2006f7 ] There are signal integrity issues running the eMMC at 200MHz on Puma RK3399-Q7. Similar to the work-around found for RK3399 Gru boards, lowering the frequency to 100MHz made the eMMC much more stable, so let's lower the frequency to 100MHz. It might be possible to run at 150MHz as on RK3399 Gru boards but only 100MHz was extensively tested. Cc: Quentin Schulz Signed-off-by: Jakob Unterwurzacher Signed-off-by: Quentin Schulz Link: https://lore.kernel.org/r/20220119134948.1444965-1-quentin.schulz@theobroma-systems.com Signed-off-by: Heiko Stuebner Signed-off-by: Sasha Levin --- arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi b/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi index 002ece51c3ba..08fa00364b42 100644 --- a/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi +++ b/arch/arm64/boot/dts/rockchip/rk3399-puma.dtsi @@ -439,6 +439,12 @@ }; &sdhci { + /* + * Signal integrity isn't great at 200MHz but 100MHz has proven stable + * enough. + */ + max-frequency = <100000000>; + bus-width = <8>; mmc-hs400-1_8v; mmc-hs400-enhanced-strobe;