spi/spi_s3c64xx: Warn if PIO transfers time out

When using PIO we have a timeout for the TX and RX FIFOs to ensure that
the data actually gets transferred. Warn if we hit that timeout - it
should never happen, but this makes sure we'll find out if it does.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Jassi Brar <jassi.brar@samsung.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

drivers/spi/spi_s3c64xx.c

@@ -200,6 +200,9 @@ static void flush_fifo(struct s3c64xx_spi_driver_data *sdd)
 		val = readl(regs + S3C64XX_SPI_STATUS);
 	} while (TX_FIFO_LVL(val, sci) && loops--);
 
+	if (loops == 0)
+		dev_warn(&sdd->pdev->dev, "Timed out flushing TX FIFO\n");
+
 	/* Flush RxFIFO*/
 	loops = msecs_to_loops(1);
 	do {
@@ -210,6 +213,9 @@ static void flush_fifo(struct s3c64xx_spi_driver_data *sdd)
 			break;
 	} while (loops--);
 
+	if (loops == 0)
+		dev_warn(&sdd->pdev->dev, "Timed out flushing RX FIFO\n");
+
 	val = readl(regs + S3C64XX_SPI_CH_CFG);
 	val &= ~S3C64XX_SPI_CH_SW_RST;
 	writel(val, regs + S3C64XX_SPI_CH_CFG);