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 67824f3bb974..610f44b24367 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 17d73459fc5f..cfbf792a0bf4 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 f8a3c4054c70..931eabe1e560 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 f9b845f4e692..d23077cca45b 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 51fdabf1fd4d..dfd6db69ead5 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;
         }
 }