dw_dmac: introduce total_len field in struct dw_desc

By this new field we distinguish a total length of the chain and the individual
length of each descriptor in the chain.

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>

drivers/dma/dw_dmac.c

@@ -333,18 +333,18 @@ dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc,
 		if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
 			if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
 				dma_unmap_single(parent, desc->lli.dar,
-						desc->len, DMA_FROM_DEVICE);
+					desc->total_len, DMA_FROM_DEVICE);
 			else
 				dma_unmap_page(parent, desc->lli.dar,
-						desc->len, DMA_FROM_DEVICE);
+					desc->total_len, DMA_FROM_DEVICE);
 		}
 		if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
 			if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
 				dma_unmap_single(parent, desc->lli.sar,
-						desc->len, DMA_TO_DEVICE);
+					desc->total_len, DMA_TO_DEVICE);
 			else
 				dma_unmap_page(parent, desc->lli.sar,
-						desc->len, DMA_TO_DEVICE);
+					desc->total_len, DMA_TO_DEVICE);
 		}
 	}
 
@@ -774,7 +774,7 @@ dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 
 	prev->lli.llp = 0;
 	first->txd.flags = flags;
-	first->len = len;
+	first->total_len = len;
 
 	return &first->txd;
 
@@ -937,7 +937,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 		prev->lli.ctllo |= DWC_CTLL_INT_EN;
 
 	prev->lli.llp = 0;
-	first->len = total_len;
+	first->total_len = total_len;
 
 	return &first->txd;
 

drivers/dma/dw_dmac_regs.h

@@ -296,6 +296,7 @@ struct dw_desc {
 	struct list_head		tx_list;
 	struct dma_async_tx_descriptor	txd;
 	size_t				len;
+	size_t				total_len;
 };
 
 #define to_dw_desc(h)	list_entry(h, struct dw_desc, desc_node)