staging: mt7621-mmc: Fix dma_map_sg may map to fewer entries

The dma_map_sg function may merge several sglist entries into one, the
return value has to be saved to consider that. The data->sg_count
field is the position, where it should be saved, like it is done in
other mmc host drivers. Also the count of mapped entries is needed for
the dma setup.

Signed-off-by: Christian Lütke-Stetzkamp <christian@lkamp.de>
Reviewed-by: NeilBrown <neil@brown.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/mt7621-mmc/sd.c b/drivers/staging/mt7621-mmc/sd.c
index d464e2a321da29284a000e916edd45e9e7965eb9..f11eb1fe3f6a716642c6b80cabadf7112a01ce55 100644 (file)
--- a/drivers/staging/mt7621-mmc/sd.c
+++ b/drivers/staging/mt7621-mmc/sd.c
@@ -1423,8 +1423,10 @@ static int msdc_do_request(struct mmc_host *mmc, struct mmc_request *mrq)
                                goto done;
 
                        dir = read ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
-                       (void)dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len, dir);
-                       msdc_dma_setup(host, &host->dma, data->sg, data->sg_len);
+                       data->sg_count = dma_map_sg(mmc_dev(mmc), data->sg,
+                                                   data->sg_len, dir);
+                       msdc_dma_setup(host, &host->dma, data->sg,
+                                      data->sg_count);
 
                        /* then wait command done */
                        if (msdc_command_resp(host, cmd, 1, CMD_TIMEOUT) != 0)