powerpc: mpic: use IRQCHIP_SKIP_SET_WAKE instead of redundant mpic_irq_set_wake

mpic_irq_set_wake return -ENXIO for non FSL MPIC and sets IRQF_NO_SUSPEND
flag for FSL ones. enable_irq_wake already returns -ENXIO if irq_set_wak
is not implemented. Also there's no need to set the IRQF_NO_SUSPEND flag
as it doesn't guarantee wakeup for that interrupt.

This patch removes the redundant mpic_irq_set_wake and sets the
IRQCHIP_SKIP_SET_WAKE for only FSL MPIC.

Cc: Benjamin Herrenschmidt <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Michael Ellerman <[e-mail]>
Cc: Scott Wood <[e-mail]>
Cc: Hongtao Jia <[e-mail]>
Cc: Marc Zyngier <[e-mail]>
Cc: [e-mail]
Signed-off-by: Sudeep Holla <[e-mail]>
Acked-by: Scott Wood <[e-mail]>
Signed-off-by: Scott Wood <[e-mail]>

arch/powerpc/sysdev/mpic.c

···
 	return IRQ_SET_MASK_OK_NOCOPY;
 }
 
-static int mpic_irq_set_wake(struct irq_data *d, unsigned int on)
-{
-	struct irq_desc *desc = container_of(d, struct irq_desc, irq_data);
-	struct mpic *mpic = mpic_from_irq_data(d);
-
-	if (!(mpic->flags & MPIC_FSL))
-		return -ENXIO;
-
-	if (on)
-		desc->action->flags |= IRQF_NO_SUSPEND;
-	else
-		desc->action->flags &= ~IRQF_NO_SUSPEND;
-
-	return 0;
-}
-
 void mpic_set_vector(unsigned int virq, unsigned int vector)
 {
 	struct mpic *mpic = mpic_from_irq(virq);
···
 	.irq_unmask	= mpic_unmask_irq,
 	.irq_eoi	= mpic_end_irq,
 	.irq_set_type	= mpic_set_irq_type,
-	.irq_set_wake	= mpic_irq_set_wake,
 };
 
 #ifdef CONFIG_SMP
···
 	.irq_mask	= mpic_mask_tm,
 	.irq_unmask	= mpic_unmask_tm,
 	.irq_eoi	= mpic_end_irq,
-	.irq_set_wake	= mpic_irq_set_wake,
 };
 
 #ifdef CONFIG_MPIC_U3_HT_IRQS
···
 		flags |= MPIC_NO_RESET;
 	if (of_get_property(node, "single-cpu-affinity", NULL))
 		flags |= MPIC_SINGLE_DEST_CPU;
-	if (of_device_is_compatible(node, "fsl,mpic"))
+	if (of_device_is_compatible(node, "fsl,mpic")) {
 		flags |= MPIC_FSL | MPIC_LARGE_VECTORS;
+		mpic_irq_chip.flags |= IRQCHIP_SKIP_SET_WAKE;
+		mpic_tm_chip.flags |= IRQCHIP_SKIP_SET_WAKE;
+	}
 
 	mpic = kzalloc(sizeof(struct mpic), GFP_KERNEL);
 	if (mpic == NULL)