irqchip: crossbar: Change allocation logic by reversing search for free irqs
Reverse the search algorithm to ensure that address mapping and IRQ
allocation logics are proper. This makes the below bugs visible sooner.
class 1. address space errors -> example:
reg = <a size_b>
ti,max-irqs = is a wrong parameter
class 2: irq-reserved list - which decides which entries in the
address space is not actually wired in
class 3: wrong list of routable-irqs.
In general allocating from max to min tends to have benefits in
ensuring the different issues that may be present in dts is easily
caught at definition time, rather than at a later point in time.
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-6-git-send-email-r.sricharan@ti.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
diff --git a/drivers/irqchip/irq-crossbar.c b/drivers/irqchip/irq-crossbar.c
index 4be30c0..a39cb31 100644
--- a/drivers/irqchip/irq-crossbar.c
+++ b/drivers/irqchip/irq-crossbar.c
@@ -58,7 +58,7 @@
{
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;
@@ -69,7 +69,7 @@
{
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;