[PATCH] irqdomain: Improve diagnostics when a domain mapping fails

[Mark Brown <broonie@opensource.wolfsonmicro.com>]

When the map operation fails log the error code we get and add a WARN_ON()
so we get a backtrace (which should help work out which interrupt is the
source of the issue).

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
---
 kernel/irq/irqdomain.c |   15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 68920c4..065a09d 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -339,11 +339,16 @@ int irq_domain_associate_many(struct irq_domain *domain, unsigned int irq_base,
 
 		irq_data->hwirq = hwirq;
 		irq_data->domain = domain;
-		if (domain->ops->map && domain->ops->map(domain, virq, hwirq)) {
-			pr_err("irq-%i==>hwirq-0x%lx mapping failed\n", virq, hwirq);
-			irq_data->domain = NULL;
-			irq_data->hwirq = 0;
-			goto err_unmap;
+		if (domain->ops->map) {
+			ret = domain->ops->map(domain, virq, hwirq);
+			if (ret != 0) {
+				pr_err("irq-%i==>hwirq-0x%lx mapping failed: %d\n",
+				       virq, hwirq, ret);
+				WARN_ON(1);
+				irq_data->domain = NULL;
+				irq_data->hwirq = 0;
+				goto err_unmap;
+			}
 		}
 
 		if (hwirq < domain->revmap_data.linear.size) {
-- 
1.7.10.4