Messages in this thread | | | Date | Thu, 22 Aug 2013 14:36:53 -0600 | From | Stephen Warren <> | Subject | Re: [PATCH v2] DMA: add help function to check whether dma controller registered |
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On 08/22/2013 12:43 AM, Richard Zhao wrote: > DMA client device driver usually needs to know at probe time whether > dma controller has been registered to deffer probe. So add a help > function of_dma_check_controller. > > DMA request channel functions can also used to check it, but they > are usually called at open() time.
This new function is almost identical to the existing of_dma_request_slave_channel(). Surely the code should be shared?
But that said, I don't see any need for a new function; why can't drivers simply call of_dma_request_slave_channel() at probe time; from what I can see, that function doesn't actually request the channel, but rather simply looks it up, just like this one. The only difference is that of_dma_xlate() is also called, but that's just doing some data transformation, not actually recording channel ownership.
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