The mips processor on PNX833x is a stubborn mips chip and takes a few
attempts to
hit the timer ack. Introduce a loop of 10 attempts to ack the timer.
cevt-r4k.c | 33 +++++++++++++++++++--------------
1 file changed, 19 insertions(+), 14 deletions(-)
Signed-off-by: daniel.j.laird <daniel.j.laird@xxxxxxx>
diff -urN --exclude=.svn
linux-2.6.26-rc4.orig/arch/mips/kernel/cevt-r4k.c
linux-2.6.26-rc4/arch/mips/kernel/cevt-r4k.c
--- linux-2.6.26-rc4.orig/arch/mips/kernel/cevt-r4k.c 2008-06-03
10:56:51.000000000 +0100
+++ linux-2.6.26-rc4/arch/mips/kernel/cevt-r4k.c 2008-06-16
14:12:18.000000000 +0100
@@ -47,11 +47,25 @@
static int cp0_timer_irq_installed;
/*
+ * FIXME: This doesn't hold for the relocated E9000 compare interrupt.
+ */
+static inline int c0_compare_int_pending(void)
+{
+ return (read_c0_cause() >> cp0_compare_irq) & 0x100;
+}
+
+/*
* Timer ack for an R4k-compatible timer of a known frequency.
*/
-static void c0_timer_ack(void)
+static inline void c0_timer_ack(bool timeout)
{
- write_c0_compare(read_c0_compare());
+ int attempts_remaining = 10;
+ do {
+ write_c0_compare(read_c0_compare());
+ irq_disable_hazard();
+ if (timeout)
+ attempts_remaining--;
+ } while (c0_compare_int_pending() && attempts_remaining);
}
/*
@@ -93,7 +107,7 @@
* interrupt. Being the paranoiacs we are we check anyway.
*/
if (!r2 || (read_c0_cause() & (1 << 30))) {
- c0_timer_ack();
+ c0_timer_ack(false);
#ifdef CONFIG_MIPS_MT_SMTC
if (cpu_data[cpu].vpe_id)
goto out;
@@ -169,13 +183,6 @@
{
}
-/*
- * FIXME: This doesn't hold for the relocated E9000 compare interrupt.
- */
-static int c0_compare_int_pending(void)
-{
- return (read_c0_cause() >> cp0_compare_irq) & 0x100;
-}
static int c0_compare_int_usable(void)
{
@@ -186,8 +193,7 @@
* IP7 already pending? Try to clear it by acking the timer.
*/
if (c0_compare_int_pending()) {
- write_c0_compare(read_c0_count());
- irq_disable_hazard();
+ c0_timer_ack(true);
if (c0_compare_int_pending())
return 0;
}
@@ -208,8 +214,7 @@
if (!c0_compare_int_pending())
return 0;
- write_c0_compare(read_c0_count());
- irq_disable_hazard();
+ c0_timer_ack(true);
if (c0_compare_int_pending())
return 0;
The mips processor on PNX833x is a stubborn mips chip and takes a few attempts to
hit the timer ack. Introduce a loop of 10 attempts to ack the timer.
cevt-r4k.c | 33 +++++++++++++++++++--------------
1 file changed, 19 insertions(+), 14 deletions(-)
Signed-off-by: daniel.j.laird <daniel.j.laird@xxxxxxx>
diff -urN --exclude=.svn linux-2.6.26-rc4.orig/arch/mips/kernel/cevt-r4k.c linux-2.6.26-rc4/arch/mips/kernel/cevt-r4k.c
--- linux-2.6.26-rc4.orig/arch/mips/kernel/cevt-r4k.c 2008-06-03 10:56:51.000000000 +0100
+++ linux-2.6.26-rc4/arch/mips/kernel/cevt-r4k.c 2008-06-16 14:12:18.000000000 +0100
@@ -47,11 +47,25 @@
static int cp0_timer_irq_installed;
/*
+ * FIXME: This doesn't hold for the relocated E9000 compare interrupt.
+ */
+static inline int c0_compare_int_pending(void)
+{
+ return (read_c0_cause() >> cp0_compare_irq) & 0x100;
+}
+
+/*
* Timer ack for an R4k-compatible timer of a known frequency.
*/
-static void c0_timer_ack(void)
+static inline void c0_timer_ack(bool timeout)
{
- write_c0_compare(read_c0_compare());
+ int attempts_remaining = 10;
+ do {
+ write_c0_compare(read_c0_compare());
+ irq_disable_hazard();
+ if (timeout)
+ attempts_remaining--;
+ } while (c0_compare_int_pending() && attempts_remaining);
}
/*
@@ -93,7 +107,7 @@
* interrupt. Being the paranoiacs we are we check anyway.
*/
if (!r2 || (read_c0_cause() & (1 << 30))) {
- c0_timer_ack();
+ c0_timer_ack(false);
#ifdef CONFIG_MIPS_MT_SMTC
if (cpu_data[cpu].vpe_id)
goto out;
@@ -169,13 +183,6 @@
{
}
-/*
- * FIXME: This doesn't hold for the relocated E9000 compare interrupt.
- */
-static int c0_compare_int_pending(void)
-{
- return (read_c0_cause() >> cp0_compare_irq) & 0x100;
-}
static int c0_compare_int_usable(void)
{
@@ -186,8 +193,7 @@
* IP7 already pending? Try to clear it by acking the timer.
*/
if (c0_compare_int_pending()) {
- write_c0_compare(read_c0_count());
- irq_disable_hazard();
+ c0_timer_ack(true);
if (c0_compare_int_pending())
return 0;
}
@@ -208,8 +214,7 @@
if (!c0_compare_int_pending())
return 0;
- write_c0_compare(read_c0_count());
- irq_disable_hazard();
+ c0_timer_ack(true);
if (c0_compare_int_pending())
return 0;
