clockevents: fix resume logic

We need to make sure, that the clockevent devices are resumed, before
the tick is resumed. The current resume logic does not guarantee this.

Add CLOCK_EVT_MODE_RESUME and call the set mode functions of the clock
event devices before resuming the tick / oneshot functionality.

Fixup the existing users.

Thanks to Nigel Cunningham for tracking down a long standing thinko,
which affected the jinxed VAIO.

[akpm@linux-foundation.org: xen build fix]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 24 insertions, 80 deletions

diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c
index 67824f3bb97..610f44b2436 100644
--- a/arch/i386/kernel/apic.c
+++ b/arch/i386/kernel/apic.c
@@ -263,6 +263,9 @@ static void lapic_timer_setup(enum clock_event_mode mode,
 		v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
 		apic_write_around(APIC_LVTT, v);
 		break;
+	case CLOCK_EVT_MODE_RESUME:
+		/* Nothing to do here */
+		break;
 	}
 
 	local_irq_restore(flags);
diff --git a/arch/i386/kernel/hpet.c b/arch/i386/kernel/hpet.c
index 17d73459fc5..cfbf792a0bf 100644
--- a/arch/i386/kernel/hpet.c
+++ b/arch/i386/kernel/hpet.c
@@ -187,6 +187,10 @@ static void hpet_set_mode(enum clock_event_mode mode,
 		cfg &= ~HPET_TN_ENABLE;
 		hpet_writel(cfg, HPET_T0_CFG);
 		break;
+
+	case CLOCK_EVT_MODE_RESUME:
+		hpet_enable_int();
+		break;
 	}
 }
 
@@ -217,6 +221,7 @@ static struct clocksource clocksource_hpet = {
 	.mask		= HPET_MASK,
 	.shift		= HPET_SHIFT,
 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+	.resume		= hpet_start_counter,
 };
 
 /*
@@ -291,7 +296,6 @@ int __init hpet_enable(void)
 
 	clocksource_register(&clocksource_hpet);
 
-
 	if (id & HPET_ID_LEGSUP) {
 		hpet_enable_int();
 		hpet_reserve_platform_timers(id);
@@ -524,68 +528,3 @@ irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 #endif
-
-
-/*
- * Suspend/resume part
- */
-
-#ifdef CONFIG_PM
-
-static int hpet_suspend(struct sys_device *sys_device, pm_message_t state)
-{
-	unsigned long cfg = hpet_readl(HPET_CFG);
-
-	cfg &= ~(HPET_CFG_ENABLE|HPET_CFG_LEGACY);
-	hpet_writel(cfg, HPET_CFG);
-
-	return 0;
-}
-
-static int hpet_resume(struct sys_device *sys_device)
-{
-	unsigned int id;
-
-	hpet_start_counter();
-
-	id = hpet_readl(HPET_ID);
-
-	if (id & HPET_ID_LEGSUP)
-		hpet_enable_int();
-
-	return 0;
-}
-
-static struct sysdev_class hpet_class = {
-	set_kset_name("hpet"),
-	.suspend	= hpet_suspend,
-	.resume		= hpet_resume,
-};
-
-static struct sys_device hpet_device = {
-	.id		= 0,
-	.cls		= &hpet_class,
-};
-
-
-static __init int hpet_register_sysfs(void)
-{
-	int err;
-
-	if (!is_hpet_capable())
-		return 0;
-
-	err = sysdev_class_register(&hpet_class);
-
-	if (!err) {
-		err = sysdev_register(&hpet_device);
-		if (err)
-			sysdev_class_unregister(&hpet_class);
-	}
-
-	return err;
-}
-
-device_initcall(hpet_register_sysfs);
-
-#endif
diff --git a/arch/i386/kernel/i8253.c b/arch/i386/kernel/i8253.c
index f8a3c4054c7..931eabe1e56 100644
--- a/arch/i386/kernel/i8253.c
+++ b/arch/i386/kernel/i8253.c
@@ -3,11 +3,11 @@
  *
  */
 #include <linux/clockchips.h>
-#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
 #include <linux/jiffies.h>
-#include <linux/sysdev.h>
 #include <linux/module.h>
-#include <linux/init.h>
+#include <linux/spinlock.h>
 
 #include <asm/smp.h>
 #include <asm/delay.h>
@@ -41,26 +41,24 @@ static void init_pit_timer(enum clock_event_mode mode,
 	case CLOCK_EVT_MODE_PERIODIC:
 		/* binary, mode 2, LSB/MSB, ch 0 */
 		outb_p(0x34, PIT_MODE);
-		udelay(10);
 		outb_p(LATCH & 0xff , PIT_CH0);	/* LSB */
-		udelay(10);
 		outb(LATCH >> 8 , PIT_CH0);	/* MSB */
 		break;
 
-	/*
-	 * Avoid unnecessary state transitions, as it confuses
-	 * Geode / Cyrix based boxen.
-	 */
 	case CLOCK_EVT_MODE_SHUTDOWN:
-		if (evt->mode == CLOCK_EVT_MODE_UNUSED)
-			break;
 	case CLOCK_EVT_MODE_UNUSED:
-		if (evt->mode == CLOCK_EVT_MODE_SHUTDOWN)
-			break;
+		outb_p(0x30, PIT_MODE);
+		outb_p(0, PIT_CH0);	/* LSB */
+		outb_p(0, PIT_CH0);	/* MSB */
+		break;
+
 	case CLOCK_EVT_MODE_ONESHOT:
 		/* One shot setup */
 		outb_p(0x38, PIT_MODE);
-		udelay(10);
+		break;
+
+	case CLOCK_EVT_MODE_RESUME:
+		/* Nothing to do here */
 		break;
 	}
 	spin_unlock_irqrestore(&i8253_lock, flags);
diff --git a/arch/i386/kernel/vmiclock.c b/arch/i386/kernel/vmiclock.c
index f9b845f4e69..d23077cca45 100644
--- a/arch/i386/kernel/vmiclock.c
+++ b/arch/i386/kernel/vmiclock.c
@@ -142,6 +142,7 @@ static void vmi_timer_set_mode(enum clock_event_mode mode,
 
 	switch (mode) {
 	case CLOCK_EVT_MODE_ONESHOT:
+	case CLOCK_EVT_MODE_RESUME:
 		break;
 	case CLOCK_EVT_MODE_PERIODIC:
 		cycles_per_hz = vmi_timer_ops.get_cycle_frequency();
diff --git a/arch/i386/xen/time.c b/arch/i386/xen/time.c
index 51fdabf1fd4..dfd6db69ead 100644
--- a/arch/i386/xen/time.c
+++ b/arch/i386/xen/time.c
@@ -412,6 +412,7 @@ static void xen_timerop_set_mode(enum clock_event_mode mode,
 		break;
 
 	case CLOCK_EVT_MODE_ONESHOT:
+	case CLOCK_EVT_MODE_RESUME:
 		break;
 
 	case CLOCK_EVT_MODE_UNUSED:
@@ -474,6 +475,8 @@ static void xen_vcpuop_set_mode(enum clock_event_mode mode,
 		    HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, cpu, NULL))
 			BUG();
 		break;
+	case CLOCK_EVT_MODE_RESUME:
+		break;
 	}
 }