[PATCH 3.16 082/346] mmc: block: fix packed command header endianness

[Ben Hutchings]

3.16.39-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Taras Kondratiuk <takondra@xxxxxxxxx>

commit f68381a70bb2b26c31b13fdaf67c778f92fd32b4 upstream.

The code that fills packed command header assumes that CPU runs in
little-endian mode. Hence the header is malformed in big-endian mode
and causes MMC data transfer errors:

[  563.200828] mmcblk0: error -110 transferring data, sector 2048, nr 8, cmd response 0x900, card status 0xc40
[  563.219647] mmcblk0: packed cmd failed, nr 2, sectors 16, failure index: -1

Convert header data to LE.

Signed-off-by: Taras Kondratiuk <takondra@xxxxxxxxx>
Fixes: ce39f9d17c14 ("mmc: support packed write command for eMMC4.5 devices")
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/mmc/card/block.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -1659,8 +1659,8 @@ static void mmc_blk_packed_hdr_wrq_prep(
 
 	packed_cmd_hdr = packed->cmd_hdr;
 	memset(packed_cmd_hdr, 0, sizeof(packed->cmd_hdr));
-	packed_cmd_hdr[0] = (packed->nr_entries << 16) |
-		(PACKED_CMD_WR << 8) | PACKED_CMD_VER;
+	packed_cmd_hdr[0] = cpu_to_le32((packed->nr_entries << 16) |
+		(PACKED_CMD_WR << 8) | PACKED_CMD_VER);
 	hdr_blocks = mmc_large_sector(card) ? 8 : 1;
 
 	/*
@@ -1674,14 +1674,14 @@ static void mmc_blk_packed_hdr_wrq_prep(
 			((brq->data.blocks * brq->data.blksz) >=
 			 card->ext_csd.data_tag_unit_size);
 		/* Argument of CMD23 */
-		packed_cmd_hdr[(i * 2)] =
+		packed_cmd_hdr[(i * 2)] = cpu_to_le32(
 			(do_rel_wr ? MMC_CMD23_ARG_REL_WR : 0) |
 			(do_data_tag ? MMC_CMD23_ARG_TAG_REQ : 0) |
-			blk_rq_sectors(prq);
+			blk_rq_sectors(prq));
 		/* Argument of CMD18 or CMD25 */
-		packed_cmd_hdr[((i * 2)) + 1] =
+		packed_cmd_hdr[((i * 2)) + 1] = cpu_to_le32(
 			mmc_card_blockaddr(card) ?
-			blk_rq_pos(prq) : blk_rq_pos(prq) << 9;
+			blk_rq_pos(prq) : blk_rq_pos(prq) << 9);
 		packed->blocks += blk_rq_sectors(prq);
 		i++;
 	}