[PATCH 3.16 257/357] gpio: Fix potential NULL handler data in chained irqchip handler

[Greg Kroah-Hartman]

3.16-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>

commit 324b0398781e7afb846378dd2d8a4374faaf236b upstream.

There is possibility with misconfigured pins that interrupt occurs instantly
after setting irq_set_chained_handler() in gpiochip_set_chained_irqchip().
Now if handler gets called before irq_set_handler_data() the handler gets
NULL handler data.

Fix this by moving irq_set_handler_data() call before
irq_set_chained_handler() in gpiochip_set_chained_irqchip().

Reviewed-by: Alexandre Courbot <acourbot@xxxxxxxxxx>
Signed-off-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpio/gpiolib.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1368,12 +1368,12 @@ void gpiochip_set_chained_irqchip(struct
 		return;
 	}
 
-	irq_set_chained_handler(parent_irq, parent_handler);
 	/*
 	 * The parent irqchip is already using the chip_data for this
 	 * irqchip, so our callbacks simply use the handler_data.
 	 */
 	irq_set_handler_data(parent_irq, gpiochip);
+	irq_set_chained_handler(parent_irq, parent_handler);
 }
 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
 


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