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

[Simon Horman]

On Tue, Apr 10, 2018 at 11:38:29AM +0200, Wolfram Sang wrote:
> From: Masaharu Hayakawa 
> 
> 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 
> [Niklas: broke this commit in two and tidied small style issue]
> Signed-off-by: Niklas Söderlund 
> [rebased to mmc/next]
> Signed-off-by: Wolfram Sang 

Reviewed-by: Simon Horman 

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

[Wolfram Sang]

From: Masaharu Hayakawa 

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 
[Niklas: broke this commit in two and tidied small style issue]
Signed-off-by: Niklas Söderlund 
[rebased to mmc/next]
Signed-off-by: Wolfram Sang 
---
 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 6c2f3ae01de9..32b8be4c0b81 100644
--- a/drivers/mmc/host/renesas_sdhi_internal_dmac.c
+++ b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
@@ -158,14 +158,20 @@ 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(>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(>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;
@@ -176,11 +182,6 @@ renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host 
*host,
dtran_mode |= DTRAN_MODE_CH_NUM_CH0;
}
 
-   ret = dma_map_sg(>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