From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754384AbcFGIuw (ORCPT ); Tue, 7 Jun 2016 04:50:52 -0400 Received: from mail-wm0-f46.google.com ([74.125.82.46]:36686 "EHLO mail-wm0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753195AbcFGIuu (ORCPT ); Tue, 7 Jun 2016 04:50:50 -0400 Date: Tue, 7 Jun 2016 09:50:45 +0100 From: Peter Griffin To: Lee Jones Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel@stlinux.com, arnd@arndb.de Subject: Re: [STLinux Kernel] [PATCH] ARM: dts: STi: stih407-family: Disable reserved-memory co-processor nodes Message-ID: <20160607085045.GA23181@griffinp-ThinkPad-X1-Carbon-2nd> References: <20160607083724.18599-1-lee.jones@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160607083724.18599-1-lee.jones@linaro.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 07 Jun 2016, Lee Jones wrote: > This patch fixes a non-booting issue in Mainline. > > When booting with a compressed kernel, we need to be careful how we > populate memory close to DDR start. AUTO_ZRELADDR is enabled by default > in multi-arch enabled configurations, which place some restrictions on > where the kernel is placed and where it will be uncompressed to on boot. > > AUTO_ZRELADDR takes the decompressor code's start address and masks out > the bottom 28 bits to obtain an address to uncompress the kernel to > (thus a load address of 0x42000000 means that the kernel will be > uncompressed to 0x40000000 i.e. DDR START on this platform). > > Even changing the load address to after the co-processor's shared memory > won't render a booting platform, since the AUTO_ZRELADDR algorithm still > ensures the kernel is uncompressed into memory shared with the first > co-processor (0x40000000). > > Another option would be to move loading to 0x4A000000, since this will > mean the decompressor will decompress the kernel to 0x48000000. However, > this would mean a large chunk (0x44000000 => 0x48000000 (64MB)) of > memory would essentially be wasted for no good reason. > > Until we can work with ST to find a suitable memory location to > relocate co-processor shared memory, let's disable the shared memory > nodes. This will ensure a working platform in the mean time. > > NB: The more observant of you will notice that we're leaving the DMU > shared memory node enabled; this is because a) it is the only one in > active use at the time of this writing and b) it is not affected by > the current default behaviour which is causing issues. > > Fixes: fe135c6 (ARM: dts: STiH407: Move over to using the 'reserved-memory' API for obtaining DMA memory) > Signed-off-by: Lee Jones > --- > arch/arm/boot/dts/stih407-family.dtsi | 3 +++ > 1 file changed, 3 insertions(+) Reviewed-by Peter Griffin