dw_dmac: return proper residue value

Currently the driver returns full length of the active descriptor which is
wrong. We have to go throught the active descriptor and substract the length of
each sent children in the chain from the total length along with the actual
data in the DMA channel registers.

The cyclic case is not handled by this patch due to len field in the descriptor
structure is left untouched by the original code.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/dma/dw_dmac_regs.h b/drivers/dma/dw_dmac_regs.h
index 833b4cf9843d..88dd8eb31957 100644
--- a/drivers/dma/dw_dmac_regs.h
+++ b/drivers/dma/dw_dmac_regs.h
@@ -203,6 +203,7 @@ struct dw_dma_chan {
         struct list_head        active_list;
         struct list_head        queue;
         struct list_head        free_list;
+        u32                     residue;
         struct dw_cyclic_desc   *cdesc;
 
         unsigned int            descs_allocated;