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 823ad72..eef145e 100644
--- a/drivers/dma/hsu/hsu.c
+++ b/drivers/dma/hsu/hsu.c
@@ -228,6 +228,8 @@
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 @@
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 @@
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 @@
enum dma_transfer_direction direction;
struct hsu_dma_sg *sg;
unsigned int nents;
+ size_t length;
unsigned int active;
enum dma_status status;
};