Hi Grant! On 2013-10-30 14:47, Grant Likely wrote:
On Fri, 11 Oct 2013 09:27:26 +0200, Marek Szyprowski<m.szyprowski@xxxxxxxxxxx> 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 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
