[PATCH] mmc: mmci: Fix PIO read for small SDIO packets

[Stefan Nilsson XK]

Corrects a bug in MMCI host driver which silently causes
small reads (< 4 bytes as only used in SDIO) from PL-18X to fail.

Signed-off-by: Stefan Nilsson XK <stefan.xk.nilsson at stericsson.com>
Signed-off-by: Ulf Hansson <ulf.hansson at stericsson.com>
Acked-by: Linus Walleij <linus.walleij at linaro.org>
---
 drivers/mmc/host/mmci.c |   13 ++++++++++++-
 1 files changed, 12 insertions(+), 1 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 56e9a41..5c3a517 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -776,7 +776,18 @@ static int mmci_pio_read(struct mmci_host *host, char *buffer, unsigned int rema
 		if (count <= 0)
 			break;
 
-		readsl(base + MMCIFIFO, ptr, count >> 2);
+		/*
+		 * SDIO especially may want to send something that is
+		 * not divisible by 4 (as opposed to card sectors
+		 * etc). Therefore make sure to to always read the last bytes
+		 * while only doing full 32-bit reads towards the FIFO.
+		 */
+		if (count < 4) {
+			unsigned char buf[4];
+			readsl(base + MMCIFIFO, buf, 1);
+			memcpy(ptr, buf, count);
+		} else
+			readsl(base + MMCIFIFO, ptr, count >> 2);
 
 		ptr += count;
 		remain -= count;
-- 
1.7.7