[PATCH 3.16 079/129] irqchip/brcmstb-l2: Use _irqsave locking variants in non-interrupt code

[Ben Hutchings]

3.16.70-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Doug Berger <open...@gmail.com>

commit 33517881ede742107f416533b8c3e4abc56763da 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.

Fixes: 7f646e92766e2 ("irqchip: brcmstb-l2: Add Broadcom Set Top Box Level-2 
interrupt controller")
Signed-off-by: Doug Berger <open...@gmail.com>
Signed-off-by: Florian Fainelli <f.faine...@gmail.com>
[maz: tidied up $SUBJECT]
Signed-off-by: Marc Zyngier <marc.zyng...@arm.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
 drivers/irqchip/irq-brcmstb-l2.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

--- a/drivers/irqchip/irq-brcmstb-l2.c
+++ b/drivers/irqchip/irq-brcmstb-l2.c
@@ -82,8 +82,9 @@ static void brcmstb_l2_intc_suspend(stru
 {
        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(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 = __raw_readl(b->base + CPU_MASK_STATUS);
 
@@ -92,22 +93,23 @@ static void brcmstb_l2_intc_suspend(stru
                __raw_writel(~gc->wake_active, b->base + CPU_MASK_SET);
                __raw_writel(gc->wake_active, b->base + CPU_MASK_CLEAR);
        }
-       irq_gc_unlock(gc);
+       irq_gc_unlock_irqrestore(gc, flags);
 }
 
 static void brcmstb_l2_intc_resume(struct irq_data *d)
 {
        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
        struct brcmstb_l2_intc_data *b = gc->private;
+       unsigned long flags;
 
-       irq_gc_lock(gc);
+       irq_gc_lock_irqsave(gc, flags);
        /* Clear unmasked non-wakeup interrupts */
        __raw_writel(~b->saved_mask & ~gc->wake_active, b->base + CPU_CLEAR);
 
        /* Restore the saved mask */
        __raw_writel(b->saved_mask, b->base + CPU_MASK_SET);
        __raw_writel(~b->saved_mask, b->base + CPU_MASK_CLEAR);
-       irq_gc_unlock(gc);
+       irq_gc_unlock_irqrestore(gc, flags);
 }
 
 int __init brcmstb_l2_intc_of_init(struct device_node *np,