3 files changed, 59 insertions, 1 deletions

diff --git a/drivers/mmc/core/sdio_bus.c b/drivers/mmc/core/sdio_bus.c
index d229020db4a2..fcb13fb0daad 100644
--- a/drivers/mmc/core/sdio_bus.c
+++ b/drivers/mmc/core/sdio_bus.c
@@ -128,11 +128,20 @@ static int sdio_bus_probe(struct device *dev)
         struct sdio_driver *drv = to_sdio_driver(dev->driver);
         struct sdio_func *func = dev_to_sdio_func(dev);
         const struct sdio_device_id *id;
+        int ret;
 
         id = sdio_match_device(func, drv);
         if (!id)
                 return -ENODEV;
 
+        /* Set the default block size so the driver is sure it's something
+         * sensible. */
+        sdio_claim_host(func);
+        ret = sdio_set_block_size(func, 0);
+        sdio_release_host(func);
+        if (ret)
+                return ret;
+
         return drv->probe(func, id);
 }
 
diff --git a/drivers/mmc/core/sdio_cis.c b/drivers/mmc/core/sdio_cis.c
index d050c40cf046..1d03f12bbb38 100644
--- a/drivers/mmc/core/sdio_cis.c
+++ b/drivers/mmc/core/sdio_cis.c
@@ -79,7 +79,7 @@ static int cistpl_funce_func(struct sdio_func *func,
                 return -EINVAL;
 
         /* TPLFE_MAX_BLK_SIZE */
-        func->blksize = buf[12] | (buf[13] << 8);
+        func->max_blksize = buf[12] | (buf[13] << 8);
 
         return 0;
 }
diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c
index ecdb77242e98..c2bad1195e3b 100644
--- a/drivers/mmc/core/sdio_io.c
+++ b/drivers/mmc/core/sdio_io.c
@@ -141,6 +141,55 @@ err:
 EXPORT_SYMBOL_GPL(sdio_disable_func);
 
 /**
+ *      sdio_set_block_size - set the block size of an SDIO function
+ *      @func: SDIO function to change
+ *      @blksz: new block size or 0 to use the default.
+ *
+ *      The default block size is the largest supported by both the function
+ *      and the host, with a maximum of 512 to ensure that arbitrarily sized
+ *      data transfer use the optimal (least) number of commands.
+ *
+ *      A driver may call this to override the default block size set by the
+ *      core. This can be used to set a block size greater than the maximum
+ *      that reported by the card; it is the driver's responsibility to ensure
+ *      it uses a value that the card supports.
+ *
+ *      Returns 0 on success, -EINVAL if the host does not support the
+ *      requested block size, or -EIO (etc.) if one of the resultant FBR block
+ *      size register writes failed.
+ *
+ */
+int sdio_set_block_size(struct sdio_func *func, unsigned blksz)
+{
+        int ret;
+
+        if (blksz > func->card->host->max_blk_size)
+                return -EINVAL;
+
+        if (blksz == 0) {
+                blksz = min(min(
+                        func->max_blksize,
+                        func->card->host->max_blk_size),
+                        512u);
+        }
+
+        ret = mmc_io_rw_direct(func->card, 1, 0,
+                SDIO_FBR_BASE(func->num) + SDIO_FBR_BLKSIZE,
+                blksz & 0xff, NULL);
+        if (ret)
+                return ret;
+        ret = mmc_io_rw_direct(func->card, 1, 0,
+                SDIO_FBR_BASE(func->num) + SDIO_FBR_BLKSIZE + 1,
+                (blksz >> 8) & 0xff, NULL);
+        if (ret)
+                return ret;
+        func->cur_blksize = blksz;
+        return 0;
+}
+
+EXPORT_SYMBOL_GPL(sdio_set_block_size);
+
+/**
  *      sdio_readb - read a single byte from a SDIO function
  *      @func: SDIO function to access
  *      @addr: address to read