66 lines
1.8 KiB
Diff
66 lines
1.8 KiB
Diff
--- 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>
|
|
|
|
+/*
|
|
+ * 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)
|
|
+
|
|
static int mips_next_event(unsigned long delta,
|
|
struct clock_event_device *evt)
|
|
{
|
|
@@ -28,6 +44,7 @@ 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 @@ static int c0_compare_int_usable(void)
|
|
*/
|
|
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 @@ static int c0_compare_int_usable(void)
|
|
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 @@ static int c0_compare_int_usable(void)
|
|
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;
|
|
|