1 files changed, 66 insertions, 33 deletions

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 27cd8c59eabf..755ab2dc6969 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -635,11 +635,14 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master,
 {
 	struct s3c64xx_spi_driver_data *sdd = spi_master_get_devdata(master);
 	const unsigned int fifo_len = (FIFO_LVL_MASK(sdd) >> 1) + 1;
+	const void *tx_buf = NULL;
+	void *rx_buf = NULL;
+	int target_len = 0, origin_len = 0;
+	int use_dma = 0;
 	int status;
 	u32 speed;
 	u8 bpw;
 	unsigned long flags;
-	int use_dma;
 
 	reinit_completion(&sdd->xfer_completion);
 
@@ -654,47 +657,77 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master,
 		s3c64xx_spi_config(sdd);
 	}
 
-	/* Polling method for xfers not bigger than FIFO capacity */
-	use_dma = 0;
 	if (!is_polling(sdd) && (xfer->len > fifo_len) &&
-	    sdd->rx_dma.ch && sdd->tx_dma.ch)
+	    sdd->rx_dma.ch && sdd->tx_dma.ch) {
 		use_dma = 1;
 
-	spin_lock_irqsave(&sdd->lock, flags);
+	} else if (is_polling(sdd) && xfer->len > fifo_len) {
+		tx_buf = xfer->tx_buf;
+		rx_buf = xfer->rx_buf;
+		origin_len = xfer->len;
 
-	/* Pending only which is to be done */
-	sdd->state &= ~RXBUSY;
-	sdd->state &= ~TXBUSY;
+		target_len = xfer->len;
+		if (xfer->len > fifo_len)
+			xfer->len = fifo_len;
+	}
+
+	do {
+		spin_lock_irqsave(&sdd->lock, flags);
 
-	s3c64xx_enable_datapath(sdd, xfer, use_dma);
+		/* Pending only which is to be done */
+		sdd->state &= ~RXBUSY;
+		sdd->state &= ~TXBUSY;
 
-	/* Start the signals */
-	s3c64xx_spi_set_cs(spi, true);
+		s3c64xx_enable_datapath(sdd, xfer, use_dma);
 
-	spin_unlock_irqrestore(&sdd->lock, flags);
+		/* Start the signals */
+		s3c64xx_spi_set_cs(spi, true);
 
-	if (use_dma)
-		status = s3c64xx_wait_for_dma(sdd, xfer);
-	else
-		status = s3c64xx_wait_for_pio(sdd, xfer);
-
-	if (status) {
-		dev_err(&spi->dev, "I/O Error: rx-%d tx-%d res:rx-%c tx-%c len-%d\n",
-			xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0,
-			(sdd->state & RXBUSY) ? 'f' : 'p',
-			(sdd->state & TXBUSY) ? 'f' : 'p',
-			xfer->len);
-
-		if (use_dma) {
-			if (xfer->tx_buf != NULL
-			    && (sdd->state & TXBUSY))
-				dmaengine_terminate_all(sdd->tx_dma.ch);
-			if (xfer->rx_buf != NULL
-			    && (sdd->state & RXBUSY))
-				dmaengine_terminate_all(sdd->rx_dma.ch);
+		spin_unlock_irqrestore(&sdd->lock, flags);
+
+		if (use_dma)
+			status = s3c64xx_wait_for_dma(sdd, xfer);
+		else
+			status = s3c64xx_wait_for_pio(sdd, xfer);
+
+		if (status) {
+			dev_err(&spi->dev,
+				"I/O Error: rx-%d tx-%d res:rx-%c tx-%c len-%d\n",
+				xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0,
+				(sdd->state & RXBUSY) ? 'f' : 'p',
+				(sdd->state & TXBUSY) ? 'f' : 'p',
+				xfer->len);
+
+			if (use_dma) {
+				if (xfer->tx_buf && (sdd->state & TXBUSY))
+					dmaengine_terminate_all(sdd->tx_dma.ch);
+				if (xfer->rx_buf && (sdd->state & RXBUSY))
+					dmaengine_terminate_all(sdd->rx_dma.ch);
+			}
+		} else {
+			s3c64xx_flush_fifo(sdd);
 		}
-	} else {
-		s3c64xx_flush_fifo(sdd);
+		if (target_len > 0) {
+			target_len -= xfer->len;
+
+			if (xfer->tx_buf)
+				xfer->tx_buf += xfer->len;
+
+			if (xfer->rx_buf)
+				xfer->rx_buf += xfer->len;
+
+			if (target_len > fifo_len)
+				xfer->len = fifo_len;
+			else
+				xfer->len = target_len;
+		}
+	} while (target_len > 0);
+
+	if (origin_len) {
+		/* Restore original xfer buffers and length */
+		xfer->tx_buf = tx_buf;
+		xfer->rx_buf = rx_buf;
+		xfer->len = origin_len;
 	}
 
 	return status;