[PATCH v2 11/11] staging: mt7621-mmc: Only unmap_sg if mapped

[George Hilliard]

A failure while processing the start command could cause dma_unmap_sg()
to be called without first calling dma_map_sg().

Since calling dma_unmap_sg() is only needed when data != NULL, move the
unmap call into the corresponding if {} block.

Signed-off-by: George Hilliard <thirtythreefo...@gmail.com>
---
 drivers/staging/mt7621-mmc/sd.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/mt7621-mmc/sd.c b/drivers/staging/mt7621-mmc/sd.c
index b52e0284ea8e..f14ff75cc4b7 100644
--- a/drivers/staging/mt7621-mmc/sd.c
+++ b/drivers/staging/mt7621-mmc/sd.c
@@ -695,7 +695,7 @@ static int msdc_do_request(struct mmc_host *mmc, struct 
mmc_request *mrq)
 
                /* then wait command done */
                if (msdc_command_resp(host, cmd, 1, CMD_TIMEOUT) != 0)
-                       goto done;
+                       goto unmap;
 
                /* for read, the data coming too fast, then CRC error
                 *  start DMA no business with CRC.
@@ -732,18 +732,17 @@ static int msdc_do_request(struct mmc_host *mmc, struct 
mmc_request *mrq)
                /* Last: stop transfer */
                if (data->stop) {
                        if (msdc_do_command(host, data->stop, 0, CMD_TIMEOUT) 
!= 0)
-                               goto done;
+                               goto unmap;
                }
-       }
 
-done:
-       if (data) {
+unmap:
                host->data = NULL;
                dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len,
                             mmc_get_dma_dir(data));
                host->blksz = 0;
        }
 
+done:
        if (mrq->cmd->error)
                host->error = 0x001;
        if (mrq->data && mrq->data->error)
-- 
2.21.0