[PATCH 12/17] spi: dw: Fix dma_slave_config used partly uninitialized

From: Serge Semin
Date: Fri May 08 2020 - 09:31:31 EST


Since the TX and RX DMA-slave config structures are declared on the
stack and only a part of their fields is initialized further in the
prepare Tx/Rx methods, the next dmaengine_slave_config() calls may
randomly perform an incorrect DMA channels setup depending on the
stack initial values. Lets fix this by zeroing the config-structures
before using them.

Co-developed-by: Georgy Vlasov <Georgy.Vlasov@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Georgy Vlasov <Georgy.Vlasov@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>
Cc: Ramil Zaripov <Ramil.Zaripov@xxxxxxxxxxxxxxxxxxxx>
Cc: Alexey Malahov <Alexey.Malahov@xxxxxxxxxxxxxxxxxxxx>
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Cc: Paul Burton <paulburton@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Allison Randal <allison@xxxxxxxxxxx>
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Gareth Williams <gareth.williams.jx@xxxxxxxxxxx>
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxxx
Cc: devicetree@xxxxxxxxxxxxxxx
---
drivers/spi/spi-dw-dma.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-dw-dma.c b/drivers/spi/spi-dw-dma.c
index d89a00fb705e..3802d2cafe91 100644
--- a/drivers/spi/spi-dw-dma.c
+++ b/drivers/spi/spi-dw-dma.c
@@ -166,7 +166,7 @@ static void dw_spi_dma_tx_done(void *arg)
static struct dma_async_tx_descriptor *dw_spi_dma_prepare_tx(struct dw_spi *dws,
struct spi_transfer *xfer)
{
- struct dma_slave_config txconf;
+ struct dma_slave_config txconf = {0};
struct dma_async_tx_descriptor *txdesc;

if (!xfer->tx_buf)
@@ -238,7 +238,7 @@ static void dw_spi_dma_rx_done(void *arg)
static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws,
struct spi_transfer *xfer)
{
- struct dma_slave_config rxconf;
+ struct dma_slave_config rxconf = {0};
struct dma_async_tx_descriptor *rxdesc;

if (!xfer->rx_buf)
--
2.25.1