1 files changed, 11 insertions, 1 deletions

diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index ab755ea26c6a..0fc90ba16ae1 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -137,7 +137,6 @@ static inline void check_wait(void)
         case CPU_4KEC:
         case CPU_4KSC:
         case CPU_5KC:
-/*      case CPU_20KC:*/
         case CPU_24K:
         case CPU_25KF:
         case CPU_34K:
@@ -156,6 +155,17 @@ static inline void check_wait(void)
                 if (allow_au1k_wait)
                         cpu_wait = au1k_wait;
                 break;
+        case CPU_20KC:
+                /*
+                 * WAIT on Rev1.0 has E1, E2, E3 and E16.
+                 * WAIT on Rev2.0 and Rev3.0 has E16.
+                 * Rev3.1 WAIT is nop, why bother
+                 */
+                if ((c->processor_id & 0xff) <= 0x64)
+                        break;
+
+                cpu_wait = r4k_wait;
+                break;
         case CPU_RM9000:
                 if ((c->processor_id & 0x00ff) >= 0x40)
                         cpu_wait = r4k_wait;