[MIPS] IP32: Fix unexpected irq 71

It's possible that the crime interrupt handler is called without
pending interrupts (probably a hardware issue). To avoid irritating
"unexpected irq 71" messages, we now just ignore the spurious crime
interrupts.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/mips/sgi-ip32/ip32-irq.c b/arch/mips/sgi-ip32/ip32-irq.c
index b0ea0e43ba48..0d6b6663d5f6 100644
--- a/arch/mips/sgi-ip32/ip32-irq.c
+++ b/arch/mips/sgi-ip32/ip32-irq.c
@@ -425,6 +425,11 @@ static void ip32_irq0(void)
         BUILD_BUG_ON(MACEISA_SERIAL2_RDMAOR_IRQ - MACEISA_AUDIO_SW_IRQ != 31);
 
         crime_int = crime->istat & crime_mask;
+
+        /* crime sometime delivers spurious interrupts, ignore them */
+        if (unlikely(crime_int == 0))
+                return;
+
         irq = MACE_VID_IN1_IRQ + __ffs(crime_int);
 
         if (crime_int & CRIME_MACEISA_INT_MASK) {