highres: improve debug output

Add some more debug information to the hrtimer and clock events code.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 14 insertions, 1 deletions

diff --git a/kernel/time/tick-oneshot.c b/kernel/time/tick-oneshot.c
index f6997ab0c3c9..0258d3115d54 100644
--- a/kernel/time/tick-oneshot.c
+++ b/kernel/time/tick-oneshot.c
@@ -73,8 +73,21 @@ int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *))
         struct clock_event_device *dev = td->evtdev;
 
         if (!dev || !(dev->features & CLOCK_EVT_FEAT_ONESHOT) ||
-            !tick_device_is_functional(dev))
+                    !tick_device_is_functional(dev)) {
+
+                printk(KERN_INFO "Clockevents: "
+                       "could not switch to one-shot mode:");
+                if (!dev) {
+                        printk(" no tick device\n");
+                } else {
+                        if (!tick_device_is_functional(dev))
+                                printk(" %s is not functional.\n", dev->name);
+                        else
+                                printk(" %s does not support one-shot mode.\n",
+                                       dev->name);
+                }
                 return -EINVAL;
+        }
 
         td->mode = TICKDEV_MODE_ONESHOT;
         dev->event_handler = handler;