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>

1 files changed, 12 insertions, 14 deletions

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);