mmc: mmci: Fix PIO read for small SDIO packets

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<[email protected]>

Signed-off-by Ulf Hansson<[email protected]>

Acked-by Linus Walleij<[email protected]>

---
  drivers/mmc/host/mmci.c |   13 ++++++++++++-
  1 files changed, 12 insertions(+), 1 deletions(-)

drivers/mmc/host/mmci.c +12 -1

index 56e9a41..5c3a517 100644
@@ -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;