Merge tag 'irqchip-4.15-4' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent

Pull irqchip updates for 4.15, take #4 from Marc Zyngier

 - A core irq fix for legacy cases where the irq trigger is not reported
   by firmware

 - A couple of GICv3/4 fixes (Kconfig, of-node refcount, error handling)

 - Trivial pr_err fixes

1 files changed, 12 insertions, 1 deletions

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 2ff1c0c82fc9..0f922729bab9 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1246,7 +1246,18 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
                  * set the trigger type must match. Also all must
                  * agree on ONESHOT.
                  */
-                unsigned int oldtype = irqd_get_trigger_type(&desc->irq_data);
+                unsigned int oldtype;
+
+                /*
+                 * If nobody did set the configuration before, inherit
+                 * the one provided by the requester.
+                 */
+                if (irqd_trigger_type_was_set(&desc->irq_data)) {
+                        oldtype = irqd_get_trigger_type(&desc->irq_data);
+                } else {
+                        oldtype = new->flags & IRQF_TRIGGER_MASK;
+                        irqd_set_trigger_type(&desc->irq_data, oldtype);
+                }
 
                 if (!((old->flags & new->flags) & IRQF_SHARED) ||
                     (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||