Subject: [PATCH] ata: Fix build error in pata_of_platform (NO_IRQ usage)

From: Anton Vorontsov <[email-masked]>
Date: Thu, 10 Nov 2011 19:18:52 +0400

This patch makes a band-aid fix the following build failure:

  CC      drivers/ata/pata_of_platform.o
drivers/ata/pata_of_platform.c: In function 'pata_of_platform_probe':
drivers/ata/pata_of_platform.c:55:13: error: 'NO_IRQ' undeclared (first use in this function)
drivers/ata/pata_of_platform.c:55:13: note: each undeclared identifier is reported only once for each function it appears in

The proper fix (stop OF code from returning NO_IRQ values) is pending.

Signed-off-by: Anton Vorontsov <[email-masked]>
---

On Thu, Nov 10, 2011 at 02:57:03PM +0100, Ingo Molnar wrote:
[...]
> > > drivers/ata/pata_of_platform.c:55:13: error: 'NO_IRQ' undeclared (first use in this function)
> > 
> > [adding Author: Anton]
> > 
> > Build error still present in linux-next of 20111014.
> 
> This build failure regression report was ignored twice and then 
> pushed upstream and is still unfixed a month after the initial 
> report. Upstream now fails to build on like 25% of x86 configs.
> 
> What's going on with this bug guys?

Here is the story:

- NO_IRQ is evil[1], AFAIR the trend is to remove its usage completely;
- Sane arches (x86) don't use it at all, or have it defined to 0
  (PPC32/64).
- On another arches it is either -1 or whatever random value;
- The NO_IRQ disease spreads despite our willingness, even within
  the new OF code.

The new irq domain stuff (that is used on ARM) always returns 0
in 'no irq' case, so we may easily remove it.

So the proper fix would be two-fold: for OF and for that driver.
But this is for 3.3 kernels. I'll send the two patches as follow-ups.

In the meantime, the band-aid (for 3.2) is down below.

[1]
http://lkml.org/lkml/2005/11/22/159
http://lkml.org/lkml/2005/11/22/227

 drivers/ata/pata_of_platform.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/drivers/ata/pata_of_platform.c b/drivers/ata/pata_of_platform.c
index a72ab0d..f99e17b 100644
--- a/drivers/ata/pata_of_platform.c
+++ b/drivers/ata/pata_of_platform.c
@@ -16,6 +16,11 @@
 #include <linux/of_platform.h>
 #include <linux/ata_platform.h>
 
+/* For archs that don't support NO_IRQ (such as x86), provide a dummy value */
+#ifndef NO_IRQ
+#define NO_IRQ 0
+#endif
+
 static int __devinit pata_of_platform_probe(struct platform_device *ofdev)
 {
 	int ret;
-- 
1.7.5.3