[PATCH] mmc: align data size for host which only supports power-of-2 block

[Bryan Wu <cooloney@kernel.org>]

From: Cliff Cai <cliff.cai@analog.com>

Signed-off-by: Cliff Cai <cliff.cai@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
---
 drivers/mmc/core/core.c  |    8 +++++++-
 include/linux/mmc/host.h |    1 +
 2 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index df6ce4a..15119df 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -321,7 +321,13 @@ unsigned int mmc_align_data_size(struct mmc_card *card, unsigned int sz)
 	 * the core about its problems yet, so for now we just 32-bit
 	 * align the size.
 	 */
-	sz = ((sz + 3) / 4) * 4;
+
+	/* Align size for host which only supports power-of-2 block */
+	if (card->host->powerof2_block) {
+		if (sz & (sz - 1))
+			sz = 1 << fls(sz);
+	} else
+		sz = ((sz + 3) / 4) * 4;
 
 	return sz;
 }
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 4e45725..7416ed1 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -162,6 +162,7 @@ struct mmc_host {
 	struct dentry		*debugfs_root;
 
 	unsigned long		private[0] ____cacheline_aligned;
+	unsigned int		powerof2_block;	/* host only supports power-of-2 block */
 };
 
 extern struct mmc_host *mmc_alloc_host(int extra, struct device *);
-- 
1.5.6.3