powerpc/52xx/media5200: Consolidate chained IRQ handler install/remove

The driver currently sets the handler data and the chained handler in
two separate steps. This creates a theoretical race window where an
interrupt could fire after the handler is set but before the data is
assigned, leading to a NULL pointer dereference.

Replace the two calls with irq_set_chained_handler_and_data() to set
both the handler and its data atomically under the irq_desc->lock.

Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260119060450.889119-1-nichen@iscas.ac.cn

Author: Chen Ni

arch/powerpc/platforms/52xx/media5200.c

@@ -176,8 +176,8 @@ static void __init media5200_init_irq(void)
 
 	of_node_put(fpga_np);
 
-	irq_set_handler_data(cascade_virq, &media5200_irq);
-	irq_set_chained_handler(cascade_virq, media5200_irq_cascade);
+	irq_set_chained_handler_and_data(cascade_virq, media5200_irq_cascade,
+					 &media5200_irq);
 
 	return;