dmaengine: hsu: speed up residue calculation

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.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/drivers/dma/hsu/hsu.c b/drivers/dma/hsu/hsu.c
index 823ad728aecff9b0e2b9810a6aad297bb1bb7d54..eef145edb936816f3686d343742a709392a5dffa 100644 (file)
--- 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 f06579c6d548d0b11b83204d0f04494d001db2d3..578a8ee8cd054429b3e3fd6da2341b49020721cc 100644 (file)
--- 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;
 };