irqchip/brcmstb-l2: Use _irqsave locking variants in non-interrupt code

commit 33517881 upstream.

Using the irq_gc_lock/irq_gc_unlock functions in the suspend and
resume functions creates the opportunity for a deadlock during
suspend, resume, and shutdown. Using the irq_gc_lock_irqsave/
irq_gc_unlock_irqrestore variants prevents this possible deadlock.

Cc: stable@vger.kernel.org
Fixes: 7f646e92 ("irqchip: brcmstb-l2: Add Broadcom Set Top Box Level-2 interrupt controller")
Signed-off-by: Doug Berger <opendmb@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
[maz: tidied up $SUBJECT]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/irqchip/irq-brcmstb-l2.c

@@ -129,8 +129,9 @@ static void brcmstb_l2_intc_suspend(struct irq_data *d)
 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
 	struct irq_chip_type *ct = irq_data_get_chip_type(d);
 	struct brcmstb_l2_intc_data *b = gc->private;
+	unsigned long flags;
 
-	irq_gc_lock(gc);
+	irq_gc_lock_irqsave(gc, flags);
 	/* Save the current mask */
 	b->saved_mask = irq_reg_readl(gc, ct->regs.mask);
 
@@ -139,7 +140,7 @@ static void brcmstb_l2_intc_suspend(struct irq_data *d)
 		irq_reg_writel(gc, ~gc->wake_active, ct->regs.disable);
 		irq_reg_writel(gc, gc->wake_active, ct->regs.enable);
 	}
-	irq_gc_unlock(gc);
+	irq_gc_unlock_irqrestore(gc, flags);
 }
 
 static void brcmstb_l2_intc_resume(struct irq_data *d)
@@ -147,8 +148,9 @@ static void brcmstb_l2_intc_resume(struct irq_data *d)
 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
 	struct irq_chip_type *ct = irq_data_get_chip_type(d);
 	struct brcmstb_l2_intc_data *b = gc->private;
+	unsigned long flags;
 
-	irq_gc_lock(gc);
+	irq_gc_lock_irqsave(gc, flags);
 	if (ct->chip.irq_ack) {
 		/* Clear unmasked non-wakeup interrupts */
 		irq_reg_writel(gc, ~b->saved_mask & ~gc->wake_active,
@@ -158,7 +160,7 @@ static void brcmstb_l2_intc_resume(struct irq_data *d)
 	/* Restore the saved mask */
 	irq_reg_writel(gc, b->saved_mask, ct->regs.disable);
 	irq_reg_writel(gc, ~b->saved_mask, ct->regs.enable);
-	irq_gc_unlock(gc);
+	irq_gc_unlock_irqrestore(gc, flags);
 }
 
 static int __init brcmstb_l2_intc_of_init(struct device_node *np,