powerpc: Remove all usages of NO_IRQ

NO_IRQ has been == 0 on powerpc for just over ten years (since commit
0ebfff1491ef ("[POWERPC] Add new interrupt mapping core and change
platforms to use it")). It's also 0 on most other arches.

Although it's fairly harmless, every now and then it causes confusion
when a driver is built on powerpc and another arch which doesn't define
NO_IRQ. There's at least 6 definitions of NO_IRQ in drivers/, at least
some of which are to work around that problem.

So we'd like to remove it. This is fairly trivial in the arch code, we
just convert:

    if (irq == NO_IRQ)	to	if (!irq)
    if (irq != NO_IRQ)	to	if (irq)
    irq = NO_IRQ;	to	irq = 0;
    return NO_IRQ;	to	return 0;

And a few other odd cases as well.

At least for now we keep the #define NO_IRQ, because there is driver
code that uses NO_IRQ and the fixes to remove those will go via other
trees.

Note we also change some occurrences in PPC sound drivers, drivers/ps3,
and drivers/macintosh.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/powerpc/platforms/cell/pmu.c b/arch/powerpc/platforms/cell/pmu.c
index 348a27b12512..e3ad0c38f017 100644
--- a/arch/powerpc/platforms/cell/pmu.c
+++ b/arch/powerpc/platforms/cell/pmu.c
@@ -385,7 +385,7 @@ static int __init cbe_init_pm_irq(void)
 	for_each_online_node(node) {
 		irq = irq_create_mapping(NULL, IIC_IRQ_IOEX_PMI |
 					       (node << IIC_IRQ_NODE_SHIFT));
-		if (irq == NO_IRQ) {
+		if (!irq) {
 			printk("ERROR: Unable to allocate irq for node %d\n",
 			       node);
 			return -EINVAL;
@@ -412,7 +412,7 @@ void cbe_sync_irq(int node)
 			       IIC_IRQ_IOEX_PMI
 			       | (node << IIC_IRQ_NODE_SHIFT));
 
-	if (irq == NO_IRQ) {
+	if (!irq) {
 		printk(KERN_WARNING "ERROR, unable to get existing irq %d " \
 		"for node %d\n", irq, node);
 		return;