[POWERPC] mpic: Fix use of uninitialized variable

Compiling ppc64_defconfig with gcc 4.3 gives thes warnings:

arch/powerpc/sysdev/mpic.c: In function 'mpic_irq_get_priority':
arch/powerpc/sysdev/mpic.c:1351: warning: 'is_ipi' may be used uninitialized in this function
arch/powerpc/sysdev/mpic.c: In function 'mpic_irq_set_priority':
arch/powerpc/sysdev/mpic.c:1328: warning: 'is_ipi' may be used uninitialized in this function

It turns out that in the cases where is_ipi is uninitialized, another
variable (mpic) will be NULL and it is dereferenced.  Protect against
this by returning if mpic is NULL in mpic_irq_set_priority, and removing
mpic_irq_get_priority completely as it has no in tree callers.

This has the nice side effect of making the warning go away.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/include/asm-powerpc/mpic.h b/include/asm-powerpc/mpic.h
index 943c5a3fac8a..a4d0f876b427 100644
--- a/include/asm-powerpc/mpic.h
+++ b/include/asm-powerpc/mpic.h
@@ -428,12 +428,11 @@ extern void mpic_init(struct mpic *mpic);
  */
 
 
-/* Change/Read the priority of an interrupt. Default is 8 for irqs and
+/* Change the priority of an interrupt. Default is 8 for irqs and
  * 10 for IPIs. You can call this on both IPIs and IRQ numbers, but the
  * IPI number is then the offset'ed (linux irq number mapped to the IPI)
  */
 extern void mpic_irq_set_priority(unsigned int irq, unsigned int pri);
-extern unsigned int mpic_irq_get_priority(unsigned int irq);
 
 /* Setup a non-boot CPU */
 extern void mpic_setup_this_cpu(void);