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, 3 insertions, 3 deletions

diff --git a/arch/powerpc/platforms/cell/axon_msi.c b/arch/powerpc/platforms/cell/axon_msi.c
index aed7714495c1..8b55c5f19d4c 100644
--- a/arch/powerpc/platforms/cell/axon_msi.c
+++ b/arch/powerpc/platforms/cell/axon_msi.c
@@ -271,7 +271,7 @@ static int axon_msi_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 
 	for_each_pci_msi_entry(entry, dev) {
 		virq = irq_create_direct_mapping(msic->irq_domain);
-		if (virq == NO_IRQ) {
+		if (!virq) {
 			dev_warn(&dev->dev,
 				 "axon_msi: virq allocation failed!\n");
 			return -1;
@@ -293,7 +293,7 @@ static void axon_msi_teardown_msi_irqs(struct pci_dev *dev)
 	dev_dbg(&dev->dev, "axon_msi: tearing down msi irqs\n");
 
 	for_each_pci_msi_entry(entry, dev) {
-		if (entry->irq == NO_IRQ)
+		if (!entry->irq)
 			continue;
 
 		irq_set_msi_desc(entry->irq, NULL);
@@ -375,7 +375,7 @@ static int axon_msi_probe(struct platform_device *device)
 	}
 
 	virq = irq_of_parse_and_map(dn, 0);
-	if (virq == NO_IRQ) {
+	if (!virq) {
 		printk(KERN_ERR "axon_msi: irq parse and map failed for %s\n",
 		       dn->full_name);
 		goto out_free_fifo;