[PATCH] Optimize i8259 code a bit.

From: Ralf Baechle
Date: Sun Oct 28 2007 - 11:51:35 EST


The timer code always calls the clock_event_device set_net_event and
set_mode methods with interrupts disabled, so no need to use
spin_lock_irqsave / spin_unlock_irqrestore for those.

arch/mips/kernel/i8253.c | 12 ++++--------
arch/x86/kernel/i8253.c | 12 ++++--------
2 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/arch/mips/kernel/i8253.c b/arch/mips/kernel/i8253.c
index 5d9830d..1b54674 100644
--- a/arch/mips/kernel/i8253.c
+++ b/arch/mips/kernel/i8253.c
@@ -23,9 +23,7 @@ static DEFINE_SPINLOCK(i8253_lock);
static void init_pit_timer(enum clock_event_mode mode,
struct clock_event_device *evt)
{
- unsigned long flags;
-
- spin_lock_irqsave(&i8253_lock, flags);
+ spin_lock(&i8253_lock);

switch(mode) {
case CLOCK_EVT_MODE_PERIODIC:
@@ -54,7 +52,7 @@ static void init_pit_timer(enum clock_event_mode mode,
/* Nothing to do here */
break;
}
- spin_unlock_irqrestore(&i8253_lock, flags);
+ spin_unlock(&i8253_lock);
}

/*
@@ -64,12 +62,10 @@ static void init_pit_timer(enum clock_event_mode mode,
*/
static int pit_next_event(unsigned long delta, struct clock_event_device *evt)
{
- unsigned long flags;
-
- spin_lock_irqsave(&i8253_lock, flags);
+ spin_lock(&i8253_lock);
outb_p(delta & 0xff , PIT_CH0); /* LSB */
outb(delta >> 8 , PIT_CH0); /* MSB */
- spin_unlock_irqrestore(&i8253_lock, flags);
+ spin_unlock(&i8253_lock);

return 0;
}
diff --git a/arch/x86/kernel/i8253.c b/arch/x86/kernel/i8253.c
index a42c807..5246515 100644
--- a/arch/x86/kernel/i8253.c
+++ b/arch/x86/kernel/i8253.c
@@ -31,9 +31,7 @@ struct clock_event_device *global_clock_event;
static void init_pit_timer(enum clock_event_mode mode,
struct clock_event_device *evt)
{
- unsigned long flags;
-
- spin_lock_irqsave(&i8253_lock, flags);
+ spin_lock(&i8253_lock);

switch(mode) {
case CLOCK_EVT_MODE_PERIODIC:
@@ -62,7 +60,7 @@ static void init_pit_timer(enum clock_event_mode mode,
/* Nothing to do here */
break;
}
- spin_unlock_irqrestore(&i8253_lock, flags);
+ spin_unlock(&i8253_lock);
}

/*
@@ -72,12 +70,10 @@ static void init_pit_timer(enum clock_event_mode mode,
*/
static int pit_next_event(unsigned long delta, struct clock_event_device *evt)
{
- unsigned long flags;
-
- spin_lock_irqsave(&i8253_lock, flags);
+ spin_lock(&i8253_lock);
outb_p(delta & 0xff , PIT_CH0); /* LSB */
outb(delta >> 8 , PIT_CH0); /* MSB */
- spin_unlock_irqrestore(&i8253_lock, flags);
+ spin_unlock(&i8253_lock);

return 0;
}
-
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