[PATCH] Due to some broken bitfiles, we can't trust IntCtl

[Raghu Gandham <raghu@mips.com>]

From: Robin Randhawa <robin@mips.com>

Signed-off-by: Chris Dearman <chris@mips.com>
---

 arch/mips/include/asm/irq.h |    1 +
 arch/mips/kernel/traps.c    |    4 ++++
 2 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/arch/mips/include/asm/irq.h b/arch/mips/include/asm/irq.h
index 09b08d0..ca0b5ed 100644
--- a/arch/mips/include/asm/irq.h
+++ b/arch/mips/include/asm/irq.h
@@ -158,6 +158,7 @@ extern void free_irqno(unsigned int irq);
  * IE7.  Since R2 their number has to be read from the c0_intctl register.
  */
 #define CP0_LEGACY_COMPARE_IRQ 7
+#define CP0_LEGACY_PERFCNT_IRQ 7
 
 extern int cp0_compare_irq;
 extern int cp0_perfcount_irq;
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 08f1edf..0b6e328 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -1538,7 +1538,11 @@ void __cpuinit per_cpu_trap_init(void)
 	 */
 	if (cpu_has_mips_r2) {
 		cp0_compare_irq = (read_c0_intctl() >> 29) & 7;
+		if (!cp0_compare_irq)
+			cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
 		cp0_perfcount_irq = (read_c0_intctl() >> 26) & 7;
+		if (!cp0_perfcount_irq)
+			cp0_perfcount_irq = CP0_LEGACY_PERFCNT_IRQ;
 		if (cp0_perfcount_irq == cp0_compare_irq)
 			cp0_perfcount_irq = -1;
 	} else {