On Tuesday, March 01, 2011 11:26 AM Edward Hervey wrote:
On Mon, 2011-02-28 at 09:50 +0100, Marek Szyprowski wrote:
I'm not sure that highmem is the right solution. First, this will force systems with rather small amount of memory (like 256M) to use highmem just to support DMA allocable memory. It also doesn't solve the issue with specific memory requirement for our DMA hardware (multimedia codec needs video memory buffers from 2 physical banks).
Could you explain why a codec would require memory buffers from 2 physical banks ?
Well, this is rather a question to hardware engineer who designed it.
I suspect that the buffers has been split into 2 regions and placed in 2 different memory banks to achieve the performance required to decode/encode full hd h264 movie. Video codec has 2 AXI master interfaces and I expect it is able to perform 2 transaction to the memory at once.
Best regards -- Marek Szyprowski Samsung Poland R&D Center