tty: serial: fsl_lpuart: make coverity happy

Message ID 20200403174942.9594-1-michael@walle.cc
State New
Headers show
Series
  • tty: serial: fsl_lpuart: make coverity happy
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Commit Message

Michael Walle April 3, 2020, 5:49 p.m.
Coverity reports the following:

  var_compare_op: Comparing chan to null implies that chan might be null.

  1234        if (chan)
  1235                dmaengine_terminate_all(chan);
  1236

  Dereference after null check (FORWARD_NULL)
  var_deref_op: Dereferencing null pointer chan.

  1237        dma_unmap_sg(chan->device->dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE);

Technically, this is correct. But lpuart_dma_rx_free() is guarded by
lpuart_dma_rx_use which is only true if there is a dma channel, see
lpuart_rx_dma_startup(). In any way, this looks bogus. So remove
the superfluous "if (chan)" check and make coverity happy.

Fixes: a092ab25fdaa ("tty: serial: fsl_lpuart: fix DMA mapping")
Signed-off-by: Michael Walle <michael@walle.cc>
Reported-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/tty/serial/fsl_lpuart.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

Patch

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 4cb04d8bf034..83d803729d23 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1210,9 +1210,7 @@  static void lpuart_dma_rx_free(struct uart_port *port)
 					struct lpuart_port, port);
 	struct dma_chan *chan = sport->dma_rx_chan;
 
-	if (chan)
-		dmaengine_terminate_all(chan);
-
+	dmaengine_terminate_all(chan);
 	dma_unmap_sg(chan->device->dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE);
 	kfree(sport->rx_ring.buf);
 	sport->rx_ring.tail = 0;