Messages in this thread | | | Date | Mon, 21 Apr 2014 09:37:08 -0500 | Subject | Re: [PATCH v2 0/7] of: setup dma parameters using dma-ranges and dma-coherent | From | Rob Herring <> |
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On Sat, Apr 19, 2014 at 9:32 AM, Santosh Shilimkar <santosh.shilimkar@ti.com> wrote: > Here is an updated version of [2] based on discussion. Series introduces > support for setting up dma parameters based on device tree properties > like 'dma-ranges' and 'dma-coherent' and also update to ARM 32 bit port. > Earlier version of the same series is here [1]. > > The 'dma-ranges' helps to take care of few DMAable system memory restrictions > by use of dma_pfn_offset which we maintain now per device. Arch code then > uses it for dma address translations for such cases. We update the > dma_pfn_offset accordingly during DT the device creation process.The > 'dma-coherent' property is used to setup arch's coherent dma_ops. > > After some off-list discussion with RMK and Arnd, I have now dropped the > controversial dma_mask setup code from the series which actually isn't blocking > me as such. Considering rest of the parts of the series are already aligned, > am hoping to get this version merged for 3.16 merge window.
Can you briefly describe what the h/w looks like in terms of addresses for the problem you are trying to solve? Something like: Cpu view of RAM is X to Y address, X corresponds to DMA address Z. Max DMA address is ?
Rob
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