On 03. 04. 20, 19:49, Michael Walle wrote:
> 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@xxxxxxxx>
> Reported-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Acked-by: Jiri Slaby <jslaby@xxxxxxx>
> ---
> drivers/tty/serial/fsl_lpuart.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> 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;
>
thanks,
--
js
suse labs
