[PATCH 5.8 161/186] dmaengine: dw-edma: Fix scatter-gather address calculation

[Greg Kroah-Hartman]

From: Gustavo Pimentel <gustavo.pimen...@synopsys.com>

commit 05655541c9503bfd01af4e6cbd7f5a29ac748e6c upstream.

Fix the source and destination physical address calculation of a
peripheral device on scatter-gather implementation.

This issue manifested during tests using a 64 bits architecture system.
The abnormal behavior wasn't visible before due to all previous tests
were done using 32 bits architecture system, that masked his effect.

Fixes: e63d79d1ffcd ("dmaengine: Add Synopsys eDMA IP core driver")
Cc: sta...@vger.kernel.org
Signed-off-by: Gustavo Pimentel <gustavo.pimen...@synopsys.com>
Link: 
https://lore.kernel.org/r/8d3ab7e2ba96563fe3495b32f60077fffb85307d.1597327623.git.gustavo.pimen...@synopsys.com
Signed-off-by: Vinod Koul <vk...@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/dma/dw-edma/dw-edma-core.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -405,7 +405,7 @@ dw_edma_device_transfer(struct dw_edma_t
                        if (xfer->cyclic) {
                                burst->dar = xfer->xfer.cyclic.paddr;
                        } else {
-                               burst->dar = sg_dma_address(sg);
+                               burst->dar = dst_addr;
                                /* Unlike the typical assumption by other
                                 * drivers/IPs the peripheral memory isn't
                                 * a FIFO memory, in this case, it's a
@@ -413,14 +413,13 @@ dw_edma_device_transfer(struct dw_edma_t
                                 * and destination addresses are increased
                                 * by the same portion (data length)
                                 */
-                               src_addr += sg_dma_len(sg);
                        }
                } else {
                        burst->dar = dst_addr;
                        if (xfer->cyclic) {
                                burst->sar = xfer->xfer.cyclic.paddr;
                        } else {
-                               burst->sar = sg_dma_address(sg);
+                               burst->sar = src_addr;
                                /* Unlike the typical assumption by other
                                 * drivers/IPs the peripheral memory isn't
                                 * a FIFO memory, in this case, it's a
@@ -428,12 +427,14 @@ dw_edma_device_transfer(struct dw_edma_t
                                 * and destination addresses are increased
                                 * by the same portion (data length)
                                 */
-                               dst_addr += sg_dma_len(sg);
                        }
                }
 
-               if (!xfer->cyclic)
+               if (!xfer->cyclic) {
+                       src_addr += sg_dma_len(sg);
+                       dst_addr += sg_dma_len(sg);
                        sg = sg_next(sg);
+               }
        }
 
        return vchan_tx_prep(&chan->vc, &desc->vd, xfer->flags);