dma: tegra: fix residual calculation for cyclic case
In cyclic mode of DMA, the byte transferred can be more
than the requested size and in this case, calculating
residuals based on the current position of DMA transfer to
bytes requested i.e. bytes required to transfer to reach
bytes requested from current DMA position.
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
index c0836a7..8e0ea24 100644
--- a/drivers/dma/tegra20-apb-dma.c
+++ b/drivers/dma/tegra20-apb-dma.c
@@ -731,6 +731,7 @@
struct tegra_dma_sg_req *sg_req;
enum dma_status ret;
unsigned long flags;
+ unsigned int residual;
spin_lock_irqsave(&tdc->lock, flags);
@@ -744,9 +745,10 @@
/* Check on wait_ack desc status */
list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) {
if (dma_desc->txd.cookie == cookie) {
- dma_set_residue(txstate,
- dma_desc->bytes_requested -
- dma_desc->bytes_transferred);
+ residual = dma_desc->bytes_requested -
+ (dma_desc->bytes_transferred %
+ dma_desc->bytes_requested);
+ dma_set_residue(txstate, residual);
ret = dma_desc->dma_status;
spin_unlock_irqrestore(&tdc->lock, flags);
return ret;
@@ -757,9 +759,10 @@
list_for_each_entry(sg_req, &tdc->pending_sg_req, node) {
dma_desc = sg_req->dma_desc;
if (dma_desc->txd.cookie == cookie) {
- dma_set_residue(txstate,
- dma_desc->bytes_requested -
- dma_desc->bytes_transferred);
+ residual = dma_desc->bytes_requested -
+ (dma_desc->bytes_transferred %
+ dma_desc->bytes_requested);
+ dma_set_residue(txstate, residual);
ret = dma_desc->dma_status;
spin_unlock_irqrestore(&tdc->lock, flags);
return ret;