Documentation :dmaengine: clarify DMA desc. pointer after submission
It clarifies that the DMA description pointer returned by `dmaengine_prep_*` function should not be used after submission. Signed-off-by: Federico Vaga <federico.vaga@cern.ch> Signed-off-by: Vinod Koul <vkoul@kernel.org>
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@ -168,6 +168,13 @@ The details of these operations are:
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dmaengine_submit() will not start the DMA operation, it merely adds
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it to the pending queue. For this, see step 5, dma_async_issue_pending.
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.. note::
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After calling ``dmaengine_submit()`` the submitted transfer descriptor
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(``struct dma_async_tx_descriptor``) belongs to the DMA engine.
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Consequently, the client must consider invalid the pointer to that
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descriptor.
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5. Issue pending DMA requests and wait for callback notification
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The transactions in the pending queue can be activated by calling the
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