[PATCH] mci: fix data write

[Sascha Hauer <s.hauer@pengutronix.de>]

The dest and src fields in struct mci_data are a union, so we cannot not
set them both to different values. Only set one of them to make write
support operational again.

Fixes: 3854311954 ("mmc: merge block read/write functions")
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/mci/mci-core.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/mci/mci-core.c b/drivers/mci/mci-core.c
index 5b892e8570..947fe44c08 100644
--- a/drivers/mci/mci-core.c
+++ b/drivers/mci/mci-core.c
@@ -360,8 +360,11 @@ static int mci_do_block_op(struct mci *mci, const void *src, void *dst, int bloc
 		mci->high_capacity != 0 ? blocknum : blocknum * mci->read_bl_len,
 		MMC_RSP_R1);
 
-	data.src = src;
-	data.dest = dst;
+	if (dst)
+		data.dest = dst;
+	else
+		data.src = src;
+
 	data.blocks = blocks;
 	data.blocksize = mci->read_bl_len;
 	data.flags = flags;
-- 
2.39.5