[PATCH v3 3/5] mmc: renesas_sdhi: Fix alignment check of sg buffer

[Wolfram Sang]

From: Masaharu Hayakawa <masaharu.hayakawa...@renesas.com>

Sometimes sg->offset is not used for buffer addresses allocated by
dma_map_sg(), so alignment checks should be done on the allocated buffer
addresses. Delete the alignment check for sg->offset that is done before
dma_map_sg(). Instead, it performs the alignment check for
sg->dma_address after dma_map_sg().

Signed-off-by: Masaharu Hayakawa <masaharu.hayakawa...@renesas.com>
[Niklas: broke this commit in two and tidied small style issue]
Signed-off-by: Niklas Söderlund <niklas.soderlund+rene...@ragnatech.se>
[rebased to mmc/next]
Signed-off-by: Wolfram Sang <wsa+rene...@sang-engineering.com>
Reviewed-by: Simon Horman <horms+rene...@verge.net.au>
---
 drivers/mmc/host/renesas_sdhi_internal_dmac.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/mmc/host/renesas_sdhi_internal_dmac.c 
b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
index 6a86619d3f85..b36e174a4b0c 100644
--- a/drivers/mmc/host/renesas_sdhi_internal_dmac.c
+++ b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
@@ -157,14 +157,20 @@ renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host 
*host,
 {
        struct scatterlist *sg = host->sg_ptr;
        u32 dtran_mode = DTRAN_MODE_BUS_WID_TH | DTRAN_MODE_ADDR_MODE;
-       int ret;
 
        /* This DMAC cannot handle if sg_len is not 1 */
        WARN_ON(host->sg_len > 1);
 
+       if (!dma_map_sg(&host->pdev->dev, sg, host->sg_len,
+                       mmc_get_dma_dir(data)))
+               goto force_pio;
+
        /* This DMAC cannot handle if buffer is not 8-bytes alignment */
-       if (!IS_ALIGNED(sg->offset, 8))
+       if (!IS_ALIGNED(sg_dma_address(sg), 8)) {
+               dma_unmap_sg(&host->pdev->dev, sg, host->sg_len,
+                            mmc_get_dma_dir(data));
                goto force_pio;
+       }
 
        if (data->flags & MMC_DATA_READ) {
                dtran_mode |= DTRAN_MODE_CH_NUM_CH1;
@@ -175,11 +181,6 @@ renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host 
*host,
                dtran_mode |= DTRAN_MODE_CH_NUM_CH0;
        }
 
-       ret = dma_map_sg(&host->pdev->dev, sg, host->sg_len,
-                        mmc_get_dma_dir(data));
-       if (ret == 0)
-               goto force_pio;
-
        renesas_sdhi_internal_dmac_enable_dma(host, true);
 
        /* set dma parameters */
-- 
2.11.0