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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 0B616C2D0A3 for ; Tue, 3 Nov 2020 18:45:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B1A9B216C4 for ; Tue, 3 Nov 2020 18:45:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=atishpatra.org header.i=@atishpatra.org header.b="Oc8HAjuJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728351AbgKCSpi (ORCPT ); Tue, 3 Nov 2020 13:45:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728969AbgKCSpi (ORCPT ); Tue, 3 Nov 2020 13:45:38 -0500 Received: from mail-io1-xd43.google.com (mail-io1-xd43.google.com [IPv6:2607:f8b0:4864:20::d43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9BCECC0617A6 for ; Tue, 3 Nov 2020 10:45:36 -0800 (PST) Received: by mail-io1-xd43.google.com with SMTP id u19so19566077ion.3 for ; Tue, 03 Nov 2020 10:45:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=atishpatra.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=OgVWTpOrMPjIuVeL2cgLMKQdzQLhuvarJci2SpLh/5A=; b=Oc8HAjuJZ68YBgtTDuQdDaeD/6Ez3BIuvplKaOikIXW6HcKAreBYOsB0tGpUmahmnu eflyjgP2lAVt36ZGob1IP6VB9qqWZRg3pA6ykiWdogLm2b0lk7Kv1sXA++RDvN9ueXc6 9mA2evAAtea8ROCk+mCHUp4aiwacb4zyghC0s= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=OgVWTpOrMPjIuVeL2cgLMKQdzQLhuvarJci2SpLh/5A=; b=UqZSn70YgYFfpFLi0yQb2yLf8OnqBriF3mvpmaZpoZHu0fuefzQ2Rpl9Q5kJVhR9Uq H9A9TSFnVB9uLAclTCRS5scbIE4K7mLh7icqQbMBzUBN3cpeQX6klxg7puEUpWxeqzOZ YLlTqhAC7Ln1ku81DzOhLBbb/QEemtxt5aM8OiRtSFbSmL5W91OJ28CJJ13WzA8iji4V GKuAVsDQe73BmoAii0U/yw12OLeSQhJUJJbJEAj9tGFUfKQ9vEMj9iXoXLz3/ospE4r5 8/wIVaaqo2d3uFxtzTihYBWtRh57hPvGPtTP7AntF+USnNcVT98SHg6rIjr+2JzBWK1g yGUA== X-Gm-Message-State: AOAM531N1hBu0Rjzgz3iD4T1ptH+bxlKOxJSf+LCFyMzCyrKXRYSYjk/ G74K24pP12WLDiRBgl5WDWHZZo3awxv5/naYTck0 X-Google-Smtp-Source: ABdhPJz1NA93CqwEifS/bxYYelWtdS7ZycUNmgghuVgW1N+oYS/M06/fanY+hPWy8svInJcHT9+EBcUwEevIx+iMc78= X-Received: by 2002:a5e:9244:: with SMTP id z4mr15350442iop.53.1604429136023; Tue, 03 Nov 2020 10:45:36 -0800 (PST) MIME-Version: 1.0 References: <20201028232759.1928479-1-atish.patra@wdc.com> <20201028232759.1928479-3-atish.patra@wdc.com> <41f1248b-78c6-bac1-410b-9e222368c5f6@codethink.co.uk> <2d7cc829-5df6-6b94-4c8f-9bae6080444e@codethink.co.uk> <22800ecc-a91b-ee3c-4717-4ee8802f31a2@codethink.co.uk> In-Reply-To: <22800ecc-a91b-ee3c-4717-4ee8802f31a2@codethink.co.uk> From: Atish Patra Date: Tue, 3 Nov 2020 10:45:24 -0800 Message-ID: Subject: Re: [RFC PATCH 2/3] RISC-V: Initial DTS for Microchip ICICLE board To: Ben Dooks Cc: Cyril.Jean@microchip.com, devicetree@vger.kernel.org, Albert Ou , Daire McNamara , Anup Patel , "linux-kernel@vger.kernel.org List" , Atish Patra , Rob Herring , Alistair Francis , Paul Walmsley , Palmer Dabbelt , linux-riscv , Padmarao Begari Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Tue, Nov 3, 2020 at 10:39 AM Ben Dooks wrote: > > On 03/11/2020 18:36, Atish Patra wrote: > > On Tue, Nov 3, 2020 at 10:28 AM Ben Dooks wrote: > >> > >> On 03/11/2020 18:10, Cyril.Jean@microchip.com wrote: > >>> On 11/3/20 3:07 PM, Atish Patra wrote: > >>>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > >>>> > >>>> On Fri, Oct 30, 2020 at 2:20 PM Ben Dooks wrote: > >> > >> ,snip[ > >> > >>>>>> @Cyril : Can we enable both eMMC & sdcard at the same time ? > >>>>> I would put /both/ in but only enable the one in use for the moment. > >>>>> Our boards are booting of eMMC as supplied, so this isn't going to work > >>>>> as well. The eMMC is 8bit wide, and thus is only delivering 11MB/sec > >>>>> instead of 22MB/sec. This performance is still not great, but losing > >>>>> half the data-rate is just not good. > >>>>> > >>>> I am not sure what should be enabled by default. Updating sdcard is much > >>>> easier than eMMC card and we use that approach. > >>>> > >>>> @Cyril: Is there a way that we can enable both ? > >>>> > >>> Yes, we can enable both but this requires a modification to the FPGA > >>> design. One of the guys prototyped this while I was away. We will move > >>> this along. This will require reprogramming the FPGA with a new design > >>> and HSS version. > >>> > >>> Regards, > >>> > >>> Cyril. > >> > >> I either missed or couldn't find a way of forcing the boot mode to be > >> from the SD slot. Have I missed something? At the moment we'd like to > >> have more storage available as the ~7G free on the eMMC is not enough. > >> > > > > I use tftpboot to load the kernel & DT from the network. SD card is > > enabled in this DT and Linux > > kernel uses SD slot instead of eMMC. > > > > To summarize, eMMC is used for HSS & U-Boot while SD card is used for > > Linux which makes > > more storage available to Linux. > > > > IMO, we should enable the sdcard for Linux DT until updated FPGA > > design & HSS is available. > > Interesting as for me the default is for Linux to use the eMMC as > well. I can't see any way for forcing the selection lines in the > DT to say eMMC vs SD. > because you are probably loading the DT passed by U-boot. I load the DTB built from the Linux source (the one present in this patch) by stopping the autoboot in U-Boot. The DT in U-Boot disables the SD card. > If there is a way of controlling the selection lines then it might > be possible to have both cards enabled with a bus selection MUX in > software. > > > -- > Ben Dooks http://www.codethink.co.uk/ > Senior Engineer Codethink - Providing Genius > > https://www.codethink.co.uk/privacy.html -- Regards, Atish