Messages in this thread |  | | Date | Wed, 6 Feb 2013 23:27:10 -0500 | Subject | DMAEngine and channel pairs | From | "" <> |
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The CPU I'm working on uses two sequential DMA channels to implement scatter-gather. How do you handle this in the channel allocator? If scatter-gather is not requested the two channels work fine as normal DMA channels.
So when a scatter-gather channel is requested my driver needs to fail the dma_alloc_chan_resources() requests until a sequential pair is located? Plus I need to track what channels are used in my driver so that I know where sequential pairs are. Is there a better way to do this?
Another solution might be to statically allocate some channels as being scatter/gather capable and others as not being able to do it. I would just report fewer available channels to dmaengine and hide those secondary channels from it. I have 12 channels to work with.
-- Jon Smirl jonsmirl@gmail.com
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