MMC: S3C24XX: Refuse incorrectly aligned transfers

The hardware does not support any multi-block transfers
with an block-size that is not 32bit aligned. Also the driver
itself does not support single block non-32bit transfers
either.

Ensure that the s3cmci_setup_data() returns the appropriate
error if we encounter this.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/mmc/host/s3cmci.c b/drivers/mmc/host/s3cmci.c
index 2b4839536975..6a1e4994b724 100644
--- a/drivers/mmc/host/s3cmci.c
+++ b/drivers/mmc/host/s3cmci.c
@@ -807,6 +807,17 @@ static int s3cmci_setup_data(struct s3cmci_host *host, struct mmc_data *data)
                 return 0;
         }
 
+        if ((data->blksz & 3) != 0) {
+                /* We cannot deal with unaligned blocks with more than
+                 * one block being transfered. */
+
+                if (data->blocks > 1)
+                        return -EINVAL;
+
+                /* No support yet for non-word block transfers. */
+                return -EINVAL;
+        }
+
         while (readl(host->base + S3C2410_SDIDSTA) &
                (S3C2410_SDIDSTA_TXDATAON | S3C2410_SDIDSTA_RXDATAON)) {