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/sysdev/mpic_msgr.c b/arch/powerpc/sysdev/mpic_msgr.c
index 3f165d972a0e..db2286be5d9a 100644
--- a/arch/powerpc/sysdev/mpic_msgr.c
+++ b/arch/powerpc/sysdev/mpic_msgr.c
@@ -238,7 +238,7 @@ static int mpic_msgr_probe(struct platform_device *dev)
 
 		if (receive_mask & (1 << i)) {
 			msgr->irq = irq_of_parse_and_map(np, irq_index);
-			if (msgr->irq == NO_IRQ) {
+			if (!msgr->irq) {
 				dev_err(&dev->dev,
 						"Missing interrupt specifier");
 				kfree(msgr);
@@ -246,7 +246,7 @@ static int mpic_msgr_probe(struct platform_device *dev)
 			}
 			irq_index += 1;
 		} else {
-			msgr->irq = NO_IRQ;
+			msgr->irq = 0;
 		}
 
 		mpic_msgrs[reg_number] = msgr;