Re: [PATCH 2/2] serial: imx: disable UCR4_OREN on shutdown

[Uwe Kleine-König]

On Thu, May 24, 2018 at 07:30:24PM +0200, Sebastian Reichel wrote:
> UCR4_OREN is (depending on the configuration) enabled in startup,
> but is never disabled. Fix this by disabling it in shutdown.
> 
> Reported-by: Nandor Han <nandor.han@xxxxxx>
> Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxxxx>
> ---
>  drivers/tty/serial/imx.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> index a0fc0327c8a5..31e1df8a8d29 100644
> --- a/drivers/tty/serial/imx.c
> +++ b/drivers/tty/serial/imx.c
> @@ -1422,7 +1422,7 @@ static void imx_uart_shutdown(struct uart_port *port)
>  {
>  	struct imx_port *sport = (struct imx_port *)port;
>  	unsigned long flags;
> -	u32 ucr1, ucr2;
> +	u32 ucr1, ucr2, ucr4;
>  
>  	if (sport->dma_is_enabled) {
>  		dmaengine_terminate_sync(sport->dma_chan_tx);
> @@ -1452,6 +1452,10 @@ static void imx_uart_shutdown(struct uart_port *port)
>  	ucr2 = imx_uart_readl(sport, UCR2);
>  	ucr2 &= ~(UCR2_TXEN | UCR2_ATEN);
>  	imx_uart_writel(sport, ucr2, UCR2);
> +
> +	ucr4 = imx_uart_readl(sport, UCR4);
> +	ucr4 &= ~UCR4_OREN;
> +	imx_uart_writel(sport, ucr4, UCR4);

Not sure this is necessary, but I assume it cannot hurt either, so

Acked-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>

Best regards
Uwe

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