[POWERPC] Fix crash in init_ipic_sysfs on efika

The global primary_ipic in arch/powerpc/sysdev/ipic.c can remain NULL
if ipic_init() fails, which will happen on machines that don't have an
ipic interrupt controller.  init_ipic_sysfs() will crash in that case.

Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Paul Mackerras <paulus@samba.org>

diff --git a/arch/powerpc/sysdev/ipic.c b/arch/powerpc/sysdev/ipic.c
index ae0dbf4..0f2dfb0 100644 (file)
--- a/arch/powerpc/sysdev/ipic.c
+++ b/arch/powerpc/sysdev/ipic.c
@@ -906,7 +906,7 @@ static int __init init_ipic_sysfs(void)
 {
        int rc;
 
-       if (!primary_ipic->regs)
+       if (!primary_ipic || !primary_ipic->regs)
                return -ENODEV;
        printk(KERN_DEBUG "Registering ipic with sysfs...\n");