spi: pxa2xx: handle error of pxa2xx_spi_dma_prepare()

If by some reason pxa2xx_spi_dma_prepare() fails we have not to ignore its
error. In such case we abort the transfer and return the error to upper
level.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[Jarkko: Avoid leaking TX descriptors in case RX descriptor allocation
fails. Noted by Robert Jarzmik <robert.jarzmik@free.fr>.
Unmap also buffers in case of failure.]
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index 85e59a4..47bdbd3 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -928,6 +928,7 @@
 	u32 dma_thresh = drv_data->cur_chip->dma_threshold;
 	u32 dma_burst = drv_data->cur_chip->dma_burst_size;
 	u32 change_mask = pxa2xx_spi_get_ssrc1_change_mask(drv_data);
+	int err;
 
 	/* Get current state information */
 	message = drv_data->cur_msg;
@@ -1047,7 +1048,12 @@
 		/* Ensure we have the correct interrupt handler */
 		drv_data->transfer_handler = pxa2xx_spi_dma_transfer;
 
-		pxa2xx_spi_dma_prepare(drv_data, dma_burst);
+		err = pxa2xx_spi_dma_prepare(drv_data, dma_burst);
+		if (err) {
+			message->status = err;
+			giveback(drv_data);
+			return;
+		}
 
 		/* Clear status and start DMA engine */
 		cr1 = chip->cr1 | dma_thresh | drv_data->dma_cr1;