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/maple/pci.c b/arch/powerpc/platforms/maple/pci.c
index a2f89e6326ce..a0589aac4163 100644
--- a/arch/powerpc/platforms/maple/pci.c
+++ b/arch/powerpc/platforms/maple/pci.c
@@ -552,7 +552,7 @@ void maple_pci_irq_fixup(struct pci_dev *dev)
 	    pci_bus_to_host(dev->bus) == u4_pcie) {
 		printk(KERN_DEBUG "Fixup U4 PCIe IRQ\n");
 		dev->irq = irq_create_mapping(NULL, 1);
-		if (dev->irq != NO_IRQ)
+		if (dev->irq)
 			irq_set_irq_type(dev->irq, IRQ_TYPE_LEVEL_LOW);
 	}
 
@@ -562,7 +562,7 @@ void maple_pci_irq_fixup(struct pci_dev *dev)
 	if (dev->vendor == PCI_VENDOR_ID_AMD &&
 	    dev->device == PCI_DEVICE_ID_AMD_8111_IDE &&
 	    (dev->class & 5) != 5) {
-		dev->irq = NO_IRQ;
+		dev->irq = 0;
 	}
 
 	DBG(" <- maple_pci_irq_fixup\n");
@@ -648,7 +648,7 @@ int maple_pci_get_legacy_ide_irq(struct pci_dev *pdev, int channel)
 		return defirq;
 	}
 	irq = irq_of_parse_and_map(np, channel & 0x1);
-	if (irq == NO_IRQ) {
+	if (!irq) {
 		printk("Failed to map onboard IDE interrupt for channel %d\n",
 		       channel);
 		return defirq;