mmc: Allow host drivers to specify a max block size

Most controllers have an upper limit on the block size. Allow the host
drivers to specify this and make sure we avoid hitting this limit.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/mmc/wbsd.c b/drivers/mmc/wbsd.c
index 7a282672f8e9..5711beecb4e8 100644
--- a/drivers/mmc/wbsd.c
+++ b/drivers/mmc/wbsd.c
@@ -1354,6 +1354,12 @@ static int __devinit wbsd_alloc_mmc(struct device *dev)
          */
         mmc->max_seg_size = mmc->max_sectors * 512;
 
+        /*
+         * Maximum block size. We have 12 bits (= 4095) but have to subtract
+         * space for CRC. So the maximum is 4095 - 4*2 = 4087.
+         */
+        mmc->max_blk_size = 4087;
+
         dev_set_drvdata(dev, mmc);
 
         return 0;