Merge remote-tracking branch 'spi/fix/mcspi' into spi-linus

drivers/spi/spi-omap2-mcspi.c

@@ -276,7 +276,7 @@ static void omap2_mcspi_set_fifo(const struct spi_device *spi,
 	struct omap2_mcspi_cs *cs = spi->controller_state;
 	struct omap2_mcspi *mcspi;
 	unsigned int wcnt;
-	int fifo_depth, bytes_per_word;
+	int max_fifo_depth, fifo_depth, bytes_per_word;
 	u32 chconf, xferlevel;
 
 	mcspi = spi_master_get_devdata(master);
@@ -287,7 +287,12 @@ static void omap2_mcspi_set_fifo(const struct spi_device *spi,
 		if (t->len % bytes_per_word != 0)
 			goto disable_fifo;
 
-		fifo_depth = gcd(t->len, OMAP2_MCSPI_MAX_FIFODEPTH);
+		if (t->rx_buf != NULL && t->tx_buf != NULL)
+			max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH / 2;
+		else
+			max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH;
+
+		fifo_depth = gcd(t->len, max_fifo_depth);
 		if (fifo_depth < 2 || fifo_depth % bytes_per_word != 0)
 			goto disable_fifo;
 
@@ -299,7 +304,8 @@ static void omap2_mcspi_set_fifo(const struct spi_device *spi,
 		if (t->rx_buf != NULL) {
 			chconf |= OMAP2_MCSPI_CHCONF_FFER;
 			xferlevel |= (fifo_depth - 1) << 8;
-		} else {
+		}
+		if (t->tx_buf != NULL) {
 			chconf |= OMAP2_MCSPI_CHCONF_FFET;
 			xferlevel |= fifo_depth - 1;
 		}