spi-topcliff-pch: add tx-memory clear after complete transmitting

Currently, in case of reading date from SPI flash,
command is sent twice.
The cause is that tx-memory clear processing is missing .
This patch adds the tx-momory clear processing.

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c
index 1d23f3831866..7a98caa3aed2 100644
--- a/drivers/spi/spi-topcliff-pch.c
+++ b/drivers/spi/spi-topcliff-pch.c
@@ -837,6 +837,11 @@ static void pch_spi_start_transfer(struct pch_spi_data *data)
 
         dma_sync_sg_for_cpu(&data->master->dev, dma->sg_rx_p, dma->nent,
                             DMA_FROM_DEVICE);
+
+        dma_sync_sg_for_cpu(&data->master->dev, dma->sg_tx_p, dma->nent,
+                            DMA_FROM_DEVICE);
+        memset(data->dma.tx_buf_virt, 0, PAGE_SIZE);
+
         async_tx_ack(dma->desc_rx);
         async_tx_ack(dma->desc_tx);
         kfree(dma->sg_tx_p);