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/drivers/ps3/ps3-vuart.c b/drivers/ps3/ps3-vuart.c
index 632701a1d993..b7f300b79ffd 100644
--- a/drivers/ps3/ps3-vuart.c
+++ b/drivers/ps3/ps3-vuart.c
@@ -958,7 +958,7 @@ static int ps3_vuart_bus_interrupt_get(void)
 
 fail_request_irq:
 	ps3_vuart_irq_destroy(vuart_bus_priv.virq);
-	vuart_bus_priv.virq = NO_IRQ;
+	vuart_bus_priv.virq = 0;
 fail_alloc_irq:
 	kfree(vuart_bus_priv.bmp);
 	vuart_bus_priv.bmp = NULL;
@@ -982,7 +982,7 @@ static int ps3_vuart_bus_interrupt_put(void)
 	free_irq(vuart_bus_priv.virq, &vuart_bus_priv);
 
 	ps3_vuart_irq_destroy(vuart_bus_priv.virq);
-	vuart_bus_priv.virq = NO_IRQ;
+	vuart_bus_priv.virq = 0;
 
 	kfree(vuart_bus_priv.bmp);
 	vuart_bus_priv.bmp = NULL;