From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Figa Subject: Re: [PATCH] ARM: dts: fix split memory bank for SSDK5440 Date: Thu, 20 Dec 2012 22:14:26 +0100 Message-ID: <1464138.NEt7mMkYJc@flatron> References: <1356030217-5472-1-git-send-email-kgene.kim@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: Received: from mail-ee0-f49.google.com ([74.125.83.49]:39734 "EHLO mail-ee0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751168Ab2LTVOa (ORCPT ); Thu, 20 Dec 2012 16:14:30 -0500 Received: by mail-ee0-f49.google.com with SMTP id c4so1993847eek.22 for ; Thu, 20 Dec 2012 13:14:28 -0800 (PST) In-Reply-To: Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Olof Johansson Cc: Kukjin Kim , linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org Hi Olof, On Thursday 20 of December 2012 11:56:59 Olof Johansson wrote: > Hi, > > On Thu, Dec 20, 2012 at 11:03 AM, Kukjin Kim wrote: > > The size of memory bank should be under 256MB, because current > > section size is 256MB on EXYNOS SoCs. This patch fixes it. > > This makes no sense. You don't have to split up memory ranges, the > code should be made to handle it instead. It's not Exynos code which causes the problem. Sparsemem initialization relies on the fact that initial amount of structures to described memory equals to maximum section size which is defined per arch (e.g. ARCH_EXYNOS). > What's the actual bug caused by this? The description is vague. The kernel panics early on NULL pointer dereference in memory initialization. Best regards, Tomasz Figa From mboxrd@z Thu Jan 1 00:00:00 1970 From: tomasz.figa@gmail.com (Tomasz Figa) Date: Thu, 20 Dec 2012 22:14:26 +0100 Subject: [PATCH] ARM: dts: fix split memory bank for SSDK5440 In-Reply-To: References: <1356030217-5472-1-git-send-email-kgene.kim@samsung.com> Message-ID: <1464138.NEt7mMkYJc@flatron> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Olof, On Thursday 20 of December 2012 11:56:59 Olof Johansson wrote: > Hi, > > On Thu, Dec 20, 2012 at 11:03 AM, Kukjin Kim wrote: > > The size of memory bank should be under 256MB, because current > > section size is 256MB on EXYNOS SoCs. This patch fixes it. > > This makes no sense. You don't have to split up memory ranges, the > code should be made to handle it instead. It's not Exynos code which causes the problem. Sparsemem initialization relies on the fact that initial amount of structures to described memory equals to maximum section size which is defined per arch (e.g. ARCH_EXYNOS). > What's the actual bug caused by this? The description is vague. The kernel panics early on NULL pointer dereference in memory initialization. Best regards, Tomasz Figa