From: m.szyprowski@samsung•com (Marek Szyprowski)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 0/2] Revert support for reserved memory regions defined in device tree
Date: Tue, 19 Nov 2013 13:27:53 +0100 [thread overview]
Message-ID: <528B5949.20204@samsung.com> (raw)
In-Reply-To: <20131030134702.19B57C402A0@trevor.secretlab.ca>
Hi Grant!
On 2013-10-30 14:47, Grant Likely wrote:
> On Fri, 11 Oct 2013 09:27:26 +0200, Marek Szyprowski<m.szyprowski@samsung•com> wrote:
> > Hi all!
> >
> > Benjamin Herrenschmidt pointed a few issues in the proposed design of
> > device tree bindings for contiguous memory allocator and reserved memory
> > regions:
> >https://lkml.org/lkml/2013/9/15/151
> >http://www.spinics.net/lists/arm-kernel/msg273548.html
> >
> > Some time has passed, but there is still no consensus on the bindings
> > for the reserved memory and various drawback of this solution has been
> > shown, so in my opinion the best I can do now is to revert them
> > completely and start from scratch again later.
>
> Hi Marek,
>
> At the ARM summit last week in Edinburgh, several of us sat down and
> hammered out a new proposal for handling reserved memory regions based
> on the work that you started here. Below you will find a new binding
> document. I started looking at implementing this, but haven't made much
> progress.
>
> Please take a look and let me know what you think.
>
> Also, while I'm thinking about it, I took another look at the code and I
> think the code supporting reserved regions should go directly into
> drivers/of/fdt.c and drivers/of/memory.c. Also, the reserved regions
> parsing should be enabled unconditionally insted of filtered by (DMA_CMA
> || (HAVE_GENERIC_DMA_COHERENT && HAVE_MEMBLOCK). If the hardware
> description says to reserve a region, then the kernel must always do so,
> even if it doesn't actually use it for anything.
Thanks for discussing this item. I'm really sorry for the late reply, but
various 'more_imporant_things(tm)' have eaten me completely last weeks.
The proposal look good for me. I'm not convinced that we really need the
support for 'reg' property, as the fixed memory region is a special case
of generic dynamic allocation specified by the size and alloc-ranges, but
I assume that there have been already a long discussion about this, so I
accept the common consensus.
Grant: have you started working on the code, which implements such binding?
If not, I will try to start do it and post the code soon for review.
Best regards
--
Marek Szyprowski
Samsung R&D Institute Poland
next prev parent reply other threads:[~2013-11-19 12:27 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-11 7:27 [PATCH 0/2] Revert support for reserved memory regions defined in device tree Marek Szyprowski
[not found] ` < 20131030134702.19B57C402A0@trevor.secretlab.ca>
2013-10-11 7:27 ` [PATCH 1/2] Revert "ARM: init: add support for reserved memory defined by device tree" Marek Szyprowski
2013-10-11 7:27 ` [PATCH 2/2] Revert "drivers: of: add initialization code for dma reserved memory" Marek Szyprowski
2013-10-11 7:48 ` [PATCH 0/2] Revert support for reserved memory regions defined in device tree Benjamin Herrenschmidt
2013-10-11 18:12 ` Kumar Gala
2013-10-15 11:41 ` Grant Likely
2013-10-17 18:37 ` Matt Sealey
2013-10-17 19:35 ` Benjamin Herrenschmidt
2013-10-15 11:40 ` Grant Likely
2013-10-15 13:27 ` Marek Szyprowski
2013-10-30 13:47 ` Grant Likely
2013-10-30 17:30 ` Matt Sealey
2013-11-19 12:27 ` Marek Szyprowski [this message]
2013-11-19 15:14 ` Grant Likely
2013-11-19 22:01 ` Benjamin Herrenschmidt
2013-11-20 13:04 ` Grant Likely
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