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| -rw-r--r-- | Documentation/dmaengine/provider.txt | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/Documentation/dmaengine/provider.txt b/Documentation/dmaengine/provider.txt index ca67b0f..243889e 100644 --- a/Documentation/dmaengine/provider.txt +++ b/Documentation/dmaengine/provider.txt @@ -345,12 +345,12 @@ where to put them) that abstracts it away. * DMA_CTRL_ACK - - If set, the transfer can be reused after being completed. - - There is a guarantee the transfer won't be freed until it is acked - by async_tx_ack(). - - As a consequence, if a device driver wants to skip the dma_map_sg() and - dma_unmap_sg() in between 2 transfers, because the DMA'd data wasn't used, - it can resubmit the transfer right after its completion. + - If clear, the descriptor cannot be reused by provider until the + client acknowledges receipt, i.e. has has a chance to establish any + dependency chains + - This can be acked by invoking async_tx_ack() + - If set, does not mean descriptor can be reused + General Design Notes -------------------- |