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FAILED: patch "[PATCH] fsl_lpuart: Don't enable interrupts too early" failed to apply to 5.4-stable tree

PATCH [email protected] 1 participant 1 message May 16, 2022

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Stable branch TTY layer and serial drivers
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The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 401fb66a355eb0f22096cf26864324f8e63c7d78 Mon Sep 17 00:00:00 2001
From: Indan Zupancic <[email protected]>
Date: Thu, 5 May 2022 13:47:50 +0200
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")
Cc stable <[email protected]>
Signed-off-by Indan Zupancic <[email protected]>
Link https://lore.kernel.org/r/[email protected] open here
Signed-off-by Greg Kroah-Hartman <[email protected]>
drivers/tty/serial/fsl_lpuart.c +9 -9
index 87789872f400..be12fee94db5 100644
@@ -2664,6 +2664,7 @@ 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);

@@ -2741,17 +2742,11 @@ 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;

@@ -2773,13 +2768,18 @@ 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);
 failed_clock_enable:
 failed_out_of_range: