--- a/arch/mips/kernel/cevt-r4k.c
+++ b/arch/mips/kernel/cevt-r4k.c
-@@ -13,6 +13,22 @@
- #include <asm/smtc_ipi.h>
- #include <asm/time.h>
+@@ -15,6 +15,22 @@
+ #include <asm/cevt-r4k.h>
-+/*
+ /*
+ * Compare interrupt can be routed and latched outside the core,
+ * so a single execution hazard barrier may not be enough to give
+ * it time to clear as seen in the Cause register. 4 time the
+ irq_disable_hazard(); \
+ } while (0)
+
- static int mips_next_event(unsigned long delta,
- struct clock_event_device *evt)
- {
-@@ -28,6 +44,7 @@
++/*
+ * The SMTC Kernel for the 34K, 1004K, et. al. replaces several
+ * of these routines with SMTC-specific variants.
+ */
+@@ -30,6 +46,7 @@ static int mips_next_event(unsigned long
cnt = read_c0_count();
cnt += delta;
write_c0_compare(cnt);
+ compare_change_hazard();
res = ((int)(read_c0_count() - cnt) > 0) ? -ETIME : 0;
- #ifdef CONFIG_MIPS_MT_SMTC
- evpe(vpflags);
-@@ -187,7 +204,7 @@
- */
- if (c0_compare_int_pending()) {
- write_c0_compare(read_c0_count());
-- irq_disable_hazard();
-+ compare_change_hazard();
- if (c0_compare_int_pending())
- return 0;
- }
-@@ -196,7 +213,7 @@
- cnt = read_c0_count();
- cnt += delta;
- write_c0_compare(cnt);
-- irq_disable_hazard();
-+ compare_change_hazard();
- if ((int)(read_c0_count() - cnt) < 0)
- break;
- /* increase delta if the timer was already expired */
-@@ -205,11 +222,12 @@
- while ((int)(read_c0_count() - cnt) <= 0)
- ; /* Wait for expiry */
-
-+ compare_change_hazard();
- if (!c0_compare_int_pending())
- return 0;
-
- write_c0_compare(read_c0_count());
-- irq_disable_hazard();
-+ compare_change_hazard();
- if (c0_compare_int_pending())
- return 0;
+ return res;
+ }
+@@ -99,22 +116,6 @@ static int c0_compare_int_pending(void)
+ return (read_c0_cause() >> cp0_compare_irq) & 0x100;
+ }
+-/*
+- * Compare interrupt can be routed and latched outside the core,
+- * so a single execution hazard barrier may not be enough to give
+- * it time to clear as seen in the Cause register. 4 time the
+- * pipeline depth seems reasonably conservative, and empirically
+- * works better in configurations with high CPU/bus clock ratios.
+- */
+-
+-#define compare_change_hazard() \
+- do { \
+- irq_disable_hazard(); \
+- irq_disable_hazard(); \
+- irq_disable_hazard(); \
+- irq_disable_hazard(); \
+- } while (0)
+-
+ int c0_compare_int_usable(void)
+ {
+ unsigned int delta;