From: Indan Zupancic Indan.Zupancic@mep-info.com

[ Upstream commit 401fb66a355eb0f22096cf26864324f8e63c7d78 ]

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") Cc: stable stable@vger.kernel.org Signed-off-by: Indan Zupancic Indan.Zupancic@mep-info.com Link: https://lore.kernel.org/r/20220505114750.45423-1-Indan.Zupancic@mep-info.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org [5.10 did not have lpuart_global_reset or anything after uart_add_one_port(), so add the remove call in cleanup manually] Signed-off-by: Dominique Martinet dominique.martinet@atmark-techno.com --- This was originally intended as a prerequirement to backport the patch submitted in [1] for 5.10, but even with that part of the patch gone it makes sense as a fix on its own.

[1] https://lkml.kernel.org/r/20221222114414.1886632-1-linux@rasmusvillemoes.dk

drivers/tty/serial/fsl_lpuart.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 43aca5a2ef0f..223695947b65 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -2586,6 +2586,7 @@ 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); @@ -2658,17 +2659,12 @@ 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_get_rs485_mode(&sport->port); if (ret) goto failed_get_rs485; @@ -2684,11 +2680,17 @@ static int lpuart_probe(struct platform_device *pdev) if (ret) goto failed_attach_port;

+ 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: + uart_remove_one_port(&lpuart_reg, &sport->port); failed_get_rs485: failed_attach_port: -failed_irq_request: lpuart_disable_clks(sport); return ret; }