On Tue, 2015-11-17 at 18:00 +0200, Andy Shevchenko wrote:
> There is no need to calculate an overall length of the descriptor
> each time we
> call for DMA transfer status. Instead we do this at descriptor
> allocation stage
> and keep the stored length for further usage.
Ping?
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
> drivers/dma/hsu/hsu.c | 17 ++++-------------
> drivers/dma/hsu/hsu.h | 1 +
> 2 files changed, 5 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/dma/hsu/hsu.c b/drivers/dma/hsu/hsu.c
> index 823ad72..eef145e 100644
> --- a/drivers/dma/hsu/hsu.c
> +++ b/drivers/dma/hsu/hsu.c
> @@ -228,6 +228,8 @@ static struct dma_async_tx_descriptor
> *hsu_dma_prep_slave_sg(
> for_each_sg(sgl, sg, sg_len, i) {
> desc->sg[i].addr = sg_dma_address(sg);
> desc->sg[i].len = sg_dma_len(sg);
> +
> + desc->length += sg_dma_len(sg);
> }
>
> desc->nents = sg_len;
> @@ -249,21 +251,10 @@ static void hsu_dma_issue_pending(struct
> dma_chan *chan)
> spin_unlock_irqrestore(&hsuc->vchan.lock, flags);
> }
>
> -static size_t hsu_dma_desc_size(struct hsu_dma_desc *desc)
> -{
> - size_t bytes = 0;
> - unsigned int i;
> -
> - for (i = desc->active; i < desc->nents; i++)
> - bytes += desc->sg[i].len;
> -
> - return bytes;
> -}
> -
> static size_t hsu_dma_active_desc_size(struct hsu_dma_chan *hsuc)
> {
> struct hsu_dma_desc *desc = hsuc->desc;
> - size_t bytes = hsu_dma_desc_size(desc);
> + size_t bytes = desc->length;
> int i;
>
> i = desc->active % HSU_DMA_CHAN_NR_DESC;
> @@ -294,7 +285,7 @@ static enum dma_status hsu_dma_tx_status(struct
> dma_chan *chan,
> dma_set_residue(state, bytes);
> status = hsuc->desc->status;
> } else if (vdesc) {
> - bytes = hsu_dma_desc_size(to_hsu_dma_desc(vdesc));
> + bytes = to_hsu_dma_desc(vdesc)->length;
> dma_set_residue(state, bytes);
> }
> spin_unlock_irqrestore(&hsuc->vchan.lock, flags);
> diff --git a/drivers/dma/hsu/hsu.h b/drivers/dma/hsu/hsu.h
> index f06579c..578a8ee 100644
> --- a/drivers/dma/hsu/hsu.h
> +++ b/drivers/dma/hsu/hsu.h
> @@ -65,6 +65,7 @@ struct hsu_dma_desc {
> enum dma_transfer_direction direction;
> struct hsu_dma_sg *sg;
> unsigned int nents;
> + size_t length;
> unsigned int active;
> enum dma_status status;
> };
--
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy
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