From: Tomasz Figa <tomasz.figa@gmail.com>
To: Olof Johansson <olof@lixom.net>
Cc: Kukjin Kim <kgene.kim@samsung.com>,
linux-arm-kernel@lists.infradead.org,
linux-samsung-soc@vger.kernel.org
Subject: Re: [PATCH] ARM: dts: fix split memory bank for SSDK5440
Date: Thu, 20 Dec 2012 22:14:26 +0100 [thread overview]
Message-ID: <1464138.NEt7mMkYJc@flatron> (raw)
In-Reply-To: <CAOesGMg03Yn=fDr1XqmbBUs=eZO0_8=iti1LUiJ6CX5n1Bm45g@mail.gmail.com>
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 <kgene.kim@samsung.com>
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
WARNING: multiple messages have this Message-ID (diff)
From: tomasz.figa@gmail.com (Tomasz Figa)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: dts: fix split memory bank for SSDK5440
Date: Thu, 20 Dec 2012 22:14:26 +0100 [thread overview]
Message-ID: <1464138.NEt7mMkYJc@flatron> (raw)
In-Reply-To: <CAOesGMg03Yn=fDr1XqmbBUs=eZO0_8=iti1LUiJ6CX5n1Bm45g@mail.gmail.com>
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 <kgene.kim@samsung.com>
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
next prev parent reply other threads:[~2012-12-20 21:14 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-20 19:03 [PATCH] ARM: dts: fix split memory bank for SSDK5440 Kukjin Kim
2012-12-20 19:03 ` Kukjin Kim
2012-12-20 19:56 ` Olof Johansson
2012-12-20 19:56 ` Olof Johansson
2012-12-20 21:14 ` Tomasz Figa [this message]
2012-12-20 21:14 ` Tomasz Figa
2012-12-20 22:19 ` Subash Patel
2012-12-20 22:19 ` Subash Patel
2012-12-20 23:18 ` Tomasz Figa
2012-12-20 23:18 ` Tomasz Figa
2012-12-21 0:43 ` Kukjin Kim
2012-12-21 0:43 ` Kukjin Kim
2012-12-20 23:41 ` Russell King - ARM Linux
2012-12-20 23:41 ` Russell King - ARM Linux
2012-12-21 0:32 ` Kukjin Kim
2012-12-21 0:32 ` Kukjin Kim
2012-12-21 0:35 ` Olof Johansson
2012-12-21 0:35 ` Olof Johansson
2012-12-21 0:56 ` Cho KyongHo
2012-12-21 0:56 ` Cho KyongHo
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