As discussed recently the meaning of DMA_CTRL_ACK is that a desc cannot be
reused by provider until the client acknowledges receipt, i.e. has has a
chance to establish any dependency chains. So update documentation
Signed-off-by: Vinod Koul <vinod.koul@xxxxxxxxx>
---
Documentation/dmaengine/provider.txt | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/Documentation/dmaengine/provider.txt b/Documentation/dmaengine/provider.txt
index ca67b0f04c6e..8b8eb7c57c1f 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 untill 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
--------------------
--
1.9.1
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