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=-6.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 5A6C9C4338F for ; Fri, 20 Aug 2021 14:49:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3153061102 for ; Fri, 20 Aug 2021 14:49:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240885AbhHTOt4 (ORCPT ); Fri, 20 Aug 2021 10:49:56 -0400 Received: from foss.arm.com ([217.140.110.172]:33536 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240879AbhHTOtz (ORCPT ); Fri, 20 Aug 2021 10:49:55 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9DA3511FB; Fri, 20 Aug 2021 07:49:17 -0700 (PDT) Received: from [10.57.15.112] (unknown [10.57.15.112]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6A67A3F70D; Fri, 20 Aug 2021 07:49:16 -0700 (PDT) Subject: Re: [PATCH] ARM: dts: rockchip: remove cap-mmc-highspeed property from mk808 &mmc0 node To: Johan Jonker , heiko@sntech.de Cc: robh+dt@kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, paweljarosz3691@gmail.com References: <20210820131920.1831-1-jbx6244@gmail.com> From: Robin Murphy Message-ID: Date: Fri, 20 Aug 2021 15:49:10 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 2021-08-20 15:41, Johan Jonker wrote: > > > On 8/20/21 4:17 PM, Robin Murphy wrote: >> On 2021-08-20 14:19, Johan Jonker wrote: >>> On the MK808 only a microSD slot is connected with the SDMMC Host >>> Controller, >>> so remove the cap-mmc-highspeed property from the &mmc0 node. >> >> Why, does it do any harm? > > Harm not. Example rk3066 u-boot: > >>>>> sd_select_mode_and_width > sd card: widths [4, 1, ] modes [MMC legacy, SD High Speed (50MHz), UHS > SDR12 (25MHz), UHS SDR25 (50MHz), ] > host: widths [4, 1, ] modes [MMC legacy, MMC High Speed (26MHz), SD > High Speed (50MHz), MMC High Speed (52MHz), ] > trying mode SD High Speed (50MHz) width 4 (at 50 MHz) > > I would say only advertise host capabilities that are under normal > circumstances occur. How realistic is it to use a TF/Micro SD TO SD Card > Extension Cable Adapter (giggle) for a deprecated mmc card? Well, if you want a far more realistic example: https://www.hardkernel.com/shop/emmc-module-reader-board-for-os-upgrade/ Who are we to dictate what "normal circumstances" are, and what do we gain by removing support for modes that could work fine and at least be useful to someone on occasion? Robin.