> -----Original Message-----
> From: Indan Zupancic <Indan.Zupancic@xxxxxxxxxxxx>
> Sent: 2022年5月5日 19:48
> To: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: Sherry Sun <sherry.sun@xxxxxxx>; dl-linux-imx <linux-imx@xxxxxxx>;
> linux-serial@xxxxxxxxxxxxxxx; jirislaby@xxxxxxxxxx; Indan Zupancic
> <Indan.Zupancic@xxxxxxxxxxxx>
> Subject: [PATCH] fsl_lpuart: Don't enable interrupts too early
>
> If an irq is pending when devm_request_irq() is called, the irq handler will
> cause a NULL pointer access because initialisation is not done yet.
>
> Fixes: 9d7ee0e28da59 ("tty: serial: lpuart: avoid report NULL interrupt")
> Signed-off-by: Indan Zupancic <Indan.Zupancic@xxxxxxxxxxxx>
Reviewed-by: Sherry Sun <sherry.sun@xxxxxxx>
Best regards
Sherry
> ---
> drivers/tty/serial/fsl_lpuart.c | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
> index 75b3c36c13bc..7b46b97a6ddd 100644
> --- a/drivers/tty/serial/fsl_lpuart.c
> +++ b/drivers/tty/serial/fsl_lpuart.c
> @@ -2629,6 +2629,7 @@ static int lpuart_probe(struct platform_device
> *pdev)
> struct device_node *np = pdev->dev.of_node;
> struct lpuart_port *sport;
> struct resource *res;
> + irq_handler_t handler;
> int ret;
>
> sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL); @@
> -2701,17 +2702,11 @@ static int lpuart_probe(struct platform_device *pdev)
>
> if (lpuart_is_32(sport)) {
> lpuart_reg.cons = LPUART32_CONSOLE;
> - ret = devm_request_irq(&pdev->dev, sport->port.irq,
> lpuart32_int, 0,
> - DRIVER_NAME, sport);
> + handler = lpuart32_int;
> } else {
> lpuart_reg.cons = LPUART_CONSOLE;
> - ret = devm_request_irq(&pdev->dev, sport->port.irq,
> lpuart_int, 0,
> - DRIVER_NAME, sport);
> + handler = lpuart_int;
> }
> -
> - if (ret)
> - goto failed_irq_request;
> -
> ret = uart_add_one_port(&lpuart_reg, &sport->port);
> if (ret)
> goto failed_attach_port;
> @@ -2733,13 +2728,18 @@ static int lpuart_probe(struct platform_device
> *pdev)
>
> sport->port.rs485_config(&sport->port, &sport->port.rs485);
>
> + ret = devm_request_irq(&pdev->dev, sport->port.irq, handler, 0,
> + DRIVER_NAME, sport);
> + if (ret)
> + goto failed_irq_request;
> +
> return 0;
>
> +failed_irq_request:
> failed_get_rs485:
> failed_reset:
> uart_remove_one_port(&lpuart_reg, &sport->port);
> failed_attach_port:
> -failed_irq_request:
> lpuart_disable_clks(sport);
> return ret;
> }
> --
> 2.30.2
