mmc: atmel-mci: conform to DMA-API

Fixes the following:
- It is perfectly legal for the dma_map_sg() to return fewer
  entries than were passed in.
- Supply the returned numer of (possibly coalesced) entries to
  the device_pre_slave_sg() function.
- Use the proper original sg_len when unmapping the sglist
  in the error path.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 3 insertions, 4 deletions

diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 045bdbbe3720..df5a13542370 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -687,10 +687,9 @@ atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data)
 
         sglen = dma_map_sg(chan->device->dev, data->sg,
                            data->sg_len, direction);
-        if (sglen != data->sg_len)
-                goto unmap_exit;
+
         desc = chan->device->device_prep_slave_sg(chan,
-                        data->sg, data->sg_len, direction,
+                        data->sg, sglen, direction,
                         DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
         if (!desc)
                 goto unmap_exit;
@@ -701,7 +700,7 @@ atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data)
 
         return 0;
 unmap_exit:
-        dma_unmap_sg(chan->device->dev, data->sg, sglen, direction);
+        dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, direction);
         return -ENOMEM;
 }