From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751345AbdAPK1E (ORCPT ); Mon, 16 Jan 2017 05:27:04 -0500 Received: from mail-lf0-f52.google.com ([209.85.215.52]:32808 "EHLO mail-lf0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750849AbdAPK1C (ORCPT ); Mon, 16 Jan 2017 05:27:02 -0500 Subject: Re: [RFT PATCH] ARM64: dts: meson-gxbb: Add reserved memory zone and usable memory range To: =?UTF-8?Q?Andreas_F=c3=a4rber?= , Heinrich Schuchardt References: <20161212101801.28491-1-narmstrong@baylibre.com> <09bb78ed-c8ec-d21f-d464-16e55c481d4e@gmx.de> <56869b90-6bee-f6ae-a7b1-884b4c0d72c0@baylibre.com> <2ac01237-a7f8-5b3b-0f97-dd49ce6623fb@gmx.de> <90d5b5a3-6dd8-aab2-8701-112a10e3364c@gmx.de> <612bc7bc-4ee4-51c0-d7ac-06151854ac03@suse.de> Cc: khilman@baylibre.com, carlo@caione.org, linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org From: Neil Armstrong Organization: Baylibre Message-ID: <9a1dbb0b-ad3d-7898-3b43-fd8f85892985@baylibre.com> Date: Mon, 16 Jan 2017 11:26:58 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <612bc7bc-4ee4-51c0-d7ac-06151854ac03@suse.de> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/15/2017 04:44 PM, Andreas Färber wrote: > Am 23.12.2016 um 10:42 schrieb Heinrich Schuchardt: >> it really makes a difference if we write >> >> memory@0 { >> device_type = "memory"; >> linux,usable-memory = <0x0 0x1000000 0x0 0x7f000000>; >> }; >> >> or >> >> memory@0 { >> device_type = "memory"; >> reg = <0x0 0x1000000 0x0 0x7f000000>; >> }; >> >> The second version leads to failure of the Odroid C2. >> >> When I looked at /sys/firmware/fdt I saw this difference: >> >> --- fails >> +++ works >> >> memory@0 { >> - device_type = "memory"; >> reg = <0x0 0x0 0x0 0x78000000>; >> + device_type = "memory"; >> + linux,usable-memory = <0x0 0x1000000 0x0 0x7f000000>; >> }; >> >> I found the following sentence in the NXP forum: >> In case you want to overwrite the memory usage passed from u-boot, you >> can use "linux,usable-memory". >> https://community.nxp.com/thread/382284 > > The Odroid-C2 is in mainline U-Boot. Please submit a patch to U-Boot > instead of forcing the creation of unnecessary new .dts files onto > everyone due to hardcoded linux,usable-memory properties. In fact, it > already reserves 0x1000000, so it seems you are merely using an older > U-Boot. > > http://git.denx.de/?p=u-boot.git;a=blob;f=arch/arm/mach-meson/board.c;h=f159cbf849f75ab046e6f3a025bbc97c0bcfd59d;hb=HEAD#l39 > > I would bet that the upper limit is unrelated here. > > Regards, > Andreas > Hi Andreas, I really disagree about relying on any work or properties added by any bootloader here, Amlogic SoCs has a lot of u-boot version in the field, and the Odroid-C2 is part of this. Even if Odroid-c2 is in mainline U-Boot or not, the mainline Linux kernel should work using any U-boot version even with the one provided by Amlogic on their openlinux distribution channel. Neil