[PATCH V2 05/19] irqchip: crossbar: Change allocation logic by reversing search for free irqs

[Sricharan R]

From: Nishanth Menon <nm at ti.com>

Reverse the search algorithm to ensure that address mapping and IRQ
allocation logics are proper. This can open up new bugs which are
easily fixable rather than wait till allocation logic approaches
the limit to find new bugs.

Signed-off-by: Nishanth Menon <nm at ti.com>
Signed-off-by: Sricharan R <r.sricharan at ti.com>
Signed-off-by: Tony Lindgren <tony at atomide.com>
---
 drivers/irqchip/irq-crossbar.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-crossbar.c b/drivers/irqchip/irq-crossbar.c
index 287d3ce..de021638 100644
--- a/drivers/irqchip/irq-crossbar.c
+++ b/drivers/irqchip/irq-crossbar.c
@@ -68,7 +68,7 @@ static inline int get_prev_map_irq(int cb_no)
 {
 	int i;
 
-	for (i = 0; i < cb->int_max; i++)
+	for (i = cb->int_max - 1; i >= 0; i--)
 		if (cb->irq_map[i] == cb_no)
 			return i;
 
@@ -79,7 +79,7 @@ static inline int allocate_free_irq(int cb_no)
 {
 	int i;
 
-	for (i = 0; i < cb->int_max; i++) {
+	for (i = cb->int_max - 1; i >= 0; i--) {
 		if (cb->irq_map[i] == IRQ_FREE) {
 			cb->irq_map[i] = cb_no;
 			return i;
-- 
1.7.9.5