From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Szyprowski Subject: Re: [PATCH] ARM: dts: exynos5422-odroidxu3: reduce total RAM by 22 MiB Date: Fri, 23 Jan 2015 08:26:59 +0100 Message-ID: <54C1F7C3.7050103@samsung.com> References: <1421842972-25807-1-git-send-email-m.szyprowski@samsung.com> <0b5601d036d6$d9628c80$8c27a580$@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mailout4.w1.samsung.com ([210.118.77.14]:32040 "EHLO mailout4.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753297AbbAWH1D (ORCPT ); Fri, 23 Jan 2015 02:27:03 -0500 Received: from eucpsbgm1.samsung.com (unknown [203.254.199.244]) by mailout4.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0NIM00BPUCVPP820@mailout4.w1.samsung.com> for linux-samsung-soc@vger.kernel.org; Fri, 23 Jan 2015 07:31:01 +0000 (GMT) In-reply-to: <0b5601d036d6$d9628c80$8c27a580$@kernel.org> Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Kukjin Kim , linux-samsung-soc@vger.kernel.org Cc: 'Javier Martinez Canillas' , jy0922.shim@samsung.com, 'Kevin Hilman' , 'Sjoerd Simons' Hello, On 2015-01-23 07:35, Kukjin Kim wrote: > Marek Szyprowski wrote: >> Last 22 MiB is RAM is reserved by secure monitor code and cannot be >> accessed from Linux kernel, so adjust total RAM size to 0x7EA00000 >> (2 GiB - 22 MiB). This fixes random 'imprecise kernel abort' kernel >> failures. >> >> Signed-off-by: Marek Szyprowski >> --- >> arch/arm/boot/dts/exynos5422-odroidxu3.dts | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/arch/arm/boot/dts/exynos5422-odroidxu3.dts b/arch/arm/boot/dts/exynos5422-odroidxu3.dts >> index f6fc9442f631..50843208860d 100644 >> --- a/arch/arm/boot/dts/exynos5422-odroidxu3.dts >> +++ b/arch/arm/boot/dts/exynos5422-odroidxu3.dts >> @@ -18,7 +18,7 @@ >> compatible = "hardkernel,odroid-xu3", "samsung,exynos5800", "samsung,exynos5"; >> >> memory { >> - reg = <0x40000000 0x80000000>; >> + reg = <0x40000000 0x7EA00000>; >> }; >> >> chosen { >> -- > Hi, > > Maybe is it related to the SoC not only for odriodxu3 board. If so, following > would be better? > > ---8<------------8<--- > diff --git a/arch/arm/boot/dts/exynos5800.dtsi b/arch/arm/boot/dts/exynos5800.dtsi > index c0bb356..54840e3 100644 > --- a/arch/arm/boot/dts/exynos5800.dtsi > +++ b/arch/arm/boot/dts/exynos5800.dtsi > @@ -13,6 +13,8 @@ > * published by the Free Software Foundation. > */ > > +/memreserve/ 0x80000000 0x1600000; > + > #include "exynos5420.dtsi" > > / { I don't think so. It is related only to the setup done by the respective board's bootloader, not the SoC itself. It is already known that exynos 5800-based Chromebooks uses different bootloader setup (BL1+BL2+Trustzone) than Odroid XU3. Also please note that u-boot for Odroid XU3 limits the total memory passed to Linux kernel to 0x7EA00000, so we should not confuse the kernel about such 'reserved' regions. The same approach is used for Odroid X2/U3. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland