[PATCH 5.15 078/102] fsl_lpuart: Dont enable interrupts too early

Greg Kroah-Hartman
2022-05-16T20:05:19Z

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

commit 401fb66a355eb0f22096cf26864324f8e63c7d78 upstream.

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>
---
drivers/tty/serial/fsl_lpuart.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -2650,6 +2650,7 @@ static int lpuart_probe(struct platform_
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);
@@ -2727,17 +2728,11 @@ static int lpuart_probe(struct platform_

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;
@@ -2759,13 +2754,18 @@ static int lpuart_probe(struct platform_

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);