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authorTony Lindgren <tony@atomide.com>2006-06-18 16:26:58 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2006-06-18 16:26:58 +0100
commitebc67da65fda03cbe5b4019d91229287fddd5c6e (patch)
tree7f1f77aa0525eecfca86f066d64938c62794e663
parent36fe6a83b4a52276eebb929ff94896fa65d83401 (diff)
downloadop-kernel-dev-ebc67da65fda03cbe5b4019d91229287fddd5c6e.zip
op-kernel-dev-ebc67da65fda03cbe5b4019d91229287fddd5c6e.tar.gz
[ARM] 3554/1: ARM: Fix dyntick locking
Patch from Tony Lindgren This patch fixes some dyntick locking issues on ARM as pointed out by Russell King. Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r--arch/arm/kernel/irq.c4
-rw-r--r--arch/arm/kernel/time.c24
-rw-r--r--include/asm-arm/mach/time.h1
3 files changed, 20 insertions, 9 deletions
diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c
index 2d5896b..bcc19fb 100644
--- a/arch/arm/kernel/irq.c
+++ b/arch/arm/kernel/irq.c
@@ -342,10 +342,10 @@ __do_irq(unsigned int irq, struct irqaction *action, struct pt_regs *regs)
#ifdef CONFIG_NO_IDLE_HZ
if (!(action->flags & SA_TIMER) && system_timer->dyn_tick != NULL) {
- write_seqlock(&xtime_lock);
+ spin_lock(&system_timer->dyn_tick->lock);
if (system_timer->dyn_tick->state & DYN_TICK_ENABLED)
system_timer->dyn_tick->handler(irq, 0, regs);
- write_sequnlock(&xtime_lock);
+ spin_unlock(&system_timer->dyn_tick->lock);
}
#endif
diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c
index d6bd435..9c12d4f 100644
--- a/arch/arm/kernel/time.c
+++ b/arch/arm/kernel/time.c
@@ -379,7 +379,7 @@ static int timer_dyn_tick_enable(void)
int ret = -ENODEV;
if (dyn_tick) {
- write_seqlock_irqsave(&xtime_lock, flags);
+ spin_lock_irqsave(&dyn_tick->lock, flags);
ret = 0;
if (!(dyn_tick->state & DYN_TICK_ENABLED)) {
ret = dyn_tick->enable();
@@ -387,7 +387,7 @@ static int timer_dyn_tick_enable(void)
if (ret == 0)
dyn_tick->state |= DYN_TICK_ENABLED;
}
- write_sequnlock_irqrestore(&xtime_lock, flags);
+ spin_unlock_irqrestore(&dyn_tick->lock, flags);
}
return ret;
@@ -400,7 +400,7 @@ static int timer_dyn_tick_disable(void)
int ret = -ENODEV;
if (dyn_tick) {
- write_seqlock_irqsave(&xtime_lock, flags);
+ spin_lock_irqsave(&dyn_tick->lock, flags);
ret = 0;
if (dyn_tick->state & DYN_TICK_ENABLED) {
ret = dyn_tick->disable();
@@ -408,7 +408,7 @@ static int timer_dyn_tick_disable(void)
if (ret == 0)
dyn_tick->state &= ~DYN_TICK_ENABLED;
}
- write_sequnlock_irqrestore(&xtime_lock, flags);
+ spin_unlock_irqrestore(&dyn_tick->lock, flags);
}
return ret;
@@ -422,15 +422,20 @@ static int timer_dyn_tick_disable(void)
void timer_dyn_reprogram(void)
{
struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick;
- unsigned long next, seq;
+ unsigned long next, seq, flags;
- if (dyn_tick && (dyn_tick->state & DYN_TICK_ENABLED)) {
+ if (!dyn_tick)
+ return;
+
+ spin_lock_irqsave(&dyn_tick->lock, flags);
+ if (dyn_tick->state & DYN_TICK_ENABLED) {
next = next_timer_interrupt();
do {
seq = read_seqbegin(&xtime_lock);
- dyn_tick->reprogram(next_timer_interrupt() - jiffies);
+ dyn_tick->reprogram(next - jiffies);
} while (read_seqretry(&xtime_lock, seq));
}
+ spin_unlock_irqrestore(&dyn_tick->lock, flags);
}
static ssize_t timer_show_dyn_tick(struct sys_device *dev, char *buf)
@@ -499,5 +504,10 @@ void __init time_init(void)
if (system_timer->offset == NULL)
system_timer->offset = dummy_gettimeoffset;
system_timer->init();
+
+#ifdef CONFIG_NO_IDLE_HZ
+ if (system_timer->dyn_tick)
+ system_timer->dyn_tick->lock = SPIN_LOCK_UNLOCKED;
+#endif
}
diff --git a/include/asm-arm/mach/time.h b/include/asm-arm/mach/time.h
index 96c6db7..9f28073 100644
--- a/include/asm-arm/mach/time.h
+++ b/include/asm-arm/mach/time.h
@@ -50,6 +50,7 @@ struct sys_timer {
#define DYN_TICK_ENABLED (1 << 1)
struct dyn_tick_timer {
+ spinlock_t lock;
unsigned int state; /* Current state */
int (*enable)(void); /* Enables dynamic tick */
int (*disable)(void); /* Disables dynamic tick */
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