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/powermac/pfunc_base.c b/arch/powerpc/platforms/powermac/pfunc_base.c
index e49d07f3d542..459138ed4571 100644
--- a/arch/powerpc/platforms/powermac/pfunc_base.c
+++ b/arch/powerpc/platforms/powermac/pfunc_base.c
@@ -26,7 +26,7 @@ static irqreturn_t macio_gpio_irq(int irq, void *data)
 static int macio_do_gpio_irq_enable(struct pmf_function *func)
 {
 	unsigned int irq = irq_of_parse_and_map(func->node, 0);
-	if (irq == NO_IRQ)
+	if (!irq)
 		return -EINVAL;
 	return request_irq(irq, macio_gpio_irq, 0, func->node->name, func);
 }
@@ -34,7 +34,7 @@ static int macio_do_gpio_irq_enable(struct pmf_function *func)
 static int macio_do_gpio_irq_disable(struct pmf_function *func)
 {
 	unsigned int irq = irq_of_parse_and_map(func->node, 0);
-	if (irq == NO_IRQ)
+	if (!irq)
 		return -EINVAL;
 	free_irq(irq, func);
 	return 0;