Re: [PATCH] tty: serial: fsl_lpuart: make coverity happy

[Fabio Estevam]

On Fri, Apr 3, 2020 at 2:50 PM Michael Walle <michael@xxxxxxxx> 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>

Reviewed-by: Fabio Estevam <festevam@xxxxxxxxx>