| Message ID | 1438744326-8400-1-git-send-email-vinod.koul@intel.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
Vinod Koul <vinod.koul@intel.com> writes: > 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@intel.com> Please take for the whole serie my : Acked-by:Robert Jarzmik <robert.jarzmik@free.fr> Cheers. -- Robert -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Aug 05, 2015 at 08:42:04AM +0530, Vinod Koul wrote: > 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 > I am applying this now
diff --git a/Documentation/dmaengine/provider.txt b/Documentation/dmaengine/provider.txt index ca67b0f04c6e..243889ec5c5a 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 --------------------
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@intel.com> --- Documentation/dmaengine/provider.txt | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)