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authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2015-11-17 19:00:30 +0300
committerVinod Koul <vinod.koul@intel.com>2015-12-05 11:30:34 +0300
commitf0579c8ceaf18adf1eca8b4404f9caac37208655 (patch)
tree9b8908cb2e7a97fa7409cc7dbf32a93ecc094a52 /drivers/dma/hsu
parentf94cf9f4c54a72ccbd2078bb0cedd3691a71c431 (diff)
downloadlinux-f0579c8ceaf18adf1eca8b4404f9caac37208655.tar.xz
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>
Diffstat (limited to 'drivers/dma/hsu')
-rw-r--r--drivers/dma/hsu/hsu.c17
-rw-r--r--drivers/dma/hsu/hsu.h1
2 files changed, 5 insertions, 13 deletions
diff --git a/drivers/dma/hsu/hsu.c b/drivers/dma/hsu/hsu.c
index 823ad728aecf..eef145edb936 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 f06579c6d548..578a8ee8cd05 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;
};