On 17-12-21, 03:58, Sanjay R Mehta wrote:
> From: Sanjay R Mehta <sanju.mehta@xxxxxxx>
>
> The command should be submitted only if the engine is idle,
> for this, the next available descriptor is checked and set the flag
> to false in case the descriptor is non-empty.
>
> Also need to segregate the cases when DMA is complete or not.
> In case if DMA is already complete there is no need to handle it
> again and gracefully exit from the function.
>
> Signed-off-by: Sanjay R Mehta <sanju.mehta@xxxxxxx>
> ---
> drivers/dma/ptdma/ptdma-dmaengine.c | 24 +++++++++++++++++-------
> 1 file changed, 17 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/dma/ptdma/ptdma-dmaengine.c b/drivers/dma/ptdma/ptdma-dmaengine.c
> index c9e52f6..91b93e8 100644
> --- a/drivers/dma/ptdma/ptdma-dmaengine.c
> +++ b/drivers/dma/ptdma/ptdma-dmaengine.c
> @@ -100,12 +100,17 @@ static struct pt_dma_desc *pt_handle_active_desc(struct pt_dma_chan *chan,
> spin_lock_irqsave(&chan->vc.lock, flags);
>
> if (desc) {
> - if (desc->status != DMA_ERROR)
> - desc->status = DMA_COMPLETE;
> -
> - dma_cookie_complete(tx_desc);
> - dma_descriptor_unmap(tx_desc);
> - list_del(&desc->vd.node);
> + if (desc->status != DMA_COMPLETE) {
> + if (desc->status != DMA_ERROR)
> + desc->status = DMA_COMPLETE;
> +
> + dma_cookie_complete(tx_desc);
> + dma_descriptor_unmap(tx_desc);
> + list_del(&desc->vd.node);
> + } else {
> + /* Don't handle it twice */
> + tx_desc = NULL;
> + }
> }
>
> desc = pt_next_dma_desc(chan);
> @@ -233,9 +238,14 @@ static void pt_issue_pending(struct dma_chan *dma_chan)
> struct pt_dma_chan *chan = to_pt_chan(dma_chan);
> struct pt_dma_desc *desc;
> unsigned long flags;
> + bool engine_is_idle = true;
>
> spin_lock_irqsave(&chan->vc.lock, flags);
>
> + desc = pt_next_dma_desc(chan);
> + if (desc)
> + engine_is_idle = false;
> +
> vchan_issue_pending(&chan->vc);
>
> desc = pt_next_dma_desc(chan);
> @@ -243,7 +253,7 @@ static void pt_issue_pending(struct dma_chan *dma_chan)
> spin_unlock_irqrestore(&chan->vc.lock, flags);
>
> /* If there was nothing active, start processing */
> - if (desc)
> + if (engine_is_idle)
Can you explain why do you need this flag and why desc is not
sufficient..
It also sounds like 2 patches to me...
> pt_cmd_callback(desc, 0);
> }
>
> --
> 2.7.4
--
~Vinod
