On Thu, Dec 16, 2021 at 08:51:21PM +0800, Jiasheng Jiang wrote:
> The return value of dma_alloc_coherent() needs to be checked.
> To avoid dereference of null pointer in case of the failure of alloc.
>
> Fixes: ab4382d27412 ("tty: move drivers/serial/ to drivers/tty/serial/")
That is not the commit that caused the problem :(
> Signed-off-by: Jiasheng Jiang <jiasheng@xxxxxxxxxxx>
> ---
> Changelog:
>
> v1 -> v2
>
> *Change 1. Add the dev_err when dma_alloc_coherent failed.
> ---
> drivers/tty/serial/pch_uart.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
> index f0351e6f0ef6..d19ed7da24fa 100644
> --- a/drivers/tty/serial/pch_uart.c
> +++ b/drivers/tty/serial/pch_uart.c
> @@ -745,6 +745,14 @@ static void pch_request_dma(struct uart_port *port)
> /* Get Consistent memory for DMA */
> priv->rx_buf_virt = dma_alloc_coherent(port->dev, port->fifosize,
> &priv->rx_buf_dma, GFP_KERNEL);
> + if (!priv->rx_buf_virt) {
> + dev_err(priv->port.dev, "%s:dma_alloc_coherent FAILS(Rx)\n",
> + __func__);
> + dma_release_channel(priv->chan_tx);
> + priv->chan_tx = NULL;
> + return;
You seemed to have ignored my previous review comments on this change
for some reason :(
This is not correct.
greg k-h
