[PATCH] [sh/highlander] psw: Add error handling in psw_irq_handler

[Haoran Liu]

This patch adds error handling for the platform_get_drvdata call
within the psw_irq_handler function in
arch/sh/boards/mach-highlander/psw.c. Previously, the absence of
error checking could lead to unexpected behavior if
platform_get_drvdata returned a null pointer.

Signed-off-by: Haoran Liu <liuhaoran14@xxxxxxx>
---
 arch/sh/boards/mach-highlander/psw.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/sh/boards/mach-highlander/psw.c b/arch/sh/boards/mach-highlander/psw.c
index d445c54f74e4..e079215e50e3 100644
--- a/arch/sh/boards/mach-highlander/psw.c
+++ b/arch/sh/boards/mach-highlander/psw.c
@@ -21,6 +21,12 @@ static irqreturn_t psw_irq_handler(int irq, void *arg)
 	unsigned int l, mask;
 	int ret = 0;
 
+	if (!psw) {
+		pr_err("psw_irq_handler: No push_switch data associated
+			with platform_device\n");
+		return IRQ_NONE;
+	}
+
 	l = __raw_readw(PA_DBSW);
 
 	/* Nothing to do if there's no state change */
-- 
2.17.1